Answer:
Explanation:
When the elevator is accelerating downwards, the apparent weight of the person is reduced, and when the elevator is accelerating upwards, the apparent weight is increased.
First, we need to determine the actual weight of the person. We can do this by using the formula:
Weight = mass x gravity
where mass is the mass of the person and gravity is the acceleration due to gravity, which is approximately 9.81 m/s^2.
Weight = (598.900 N) / (9.81 m/s^2) = 61.048 kg
Now, when the elevator is not moving, the person is only experiencing the force due to gravity, which is:
Weight = mass x gravity = (61.048 kg) x (9.81 m/s^2) = 598.78 N
Therefore, the scale would read approximately 598.78 Newtons when the elevator is not moving.
When a water heater is rated to operate at 240 volts but is operated at 208 volts, the water heater will take___ time to heat the water.Select one:a. moreb. the samec. less
a. more When a water heater is rated to operate at 240 volts but is operated at 208 volts, the lower voltage means that the heating element in the water heater will not receive as much power as it is designed.
What is a power ?Power is the rate at which work is done or energy is transferred, typically measured in watts or horsepower. It represents the amount of energy used or transferred per unit time.
Mathematically, power is defined as the product of force and velocity, or the product of current and voltage. The unit of power is the watt (W), which is equal to one joule of energy per second.Power is an important concept in physics, engineering, and technology. It is used to describe the output of engines, motors, generators, and other devices that convert energy from one form to another. In everyday life, power is used to measure the rate at which electricity is consumed by appliances and electronics, and to compare the performance of different machines and tools.
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Please do help me. Nonsense answers will be reported.
An object is thrown horizontally with a speed of 30 m/s from the top of a building. Complete the table below for the indicated time interval. Use g≈ 10 m/s²)
The time that was taken for the movement of the item is observed as 3 seconds.
How do you use the equations of motion?The equations of motion describe the motion of objects in terms of their position, velocity, acceleration, and time.
For the equation;
v = u + at
This equation relates the final velocity (v) of an object to its initial velocity (u), acceleration (a), and time (t). If three of these variables are known, the equation can be rearranged to solve for the unknown variable.
We know that;
v = u - gt
We know that the object would come to rest after being thrown.
0 = 30 - 10t
-30 = - 10t
t = 3 seconds
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I need some help with this problem
Tensile force refers to the stretching forces that operate on a substance and consists of two components: tensile tension and tensile strain. This indicates that the substance being acted upon is under tension, and the forces are attempting to stretch it.
What Does Tensile Force Mean?Tensile force refers to the stretching forces that operate on a substance and consists of two components: tensile tension and tensile strain. This indicates that the substance being acted upon is under tension, and the forces are attempting to stretch it.
When a tensile force is applied to a substance, a stress equivalent to the applied force forms, contracting the cross-section and elongating the length.
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center of mass vs gravity
In most mechanics problems the gravitational field is assumed to be uniform. The center of gravity is then in exactly the same position as the center of mass. The terms center of gravity and center of mass tend to often be used interchangeably since they are often at the same location
a battleship simultaneously fires two shells at enemy ships. if the shells follow the parabolic trajectories shown, which ship gets hit first?
A battleship simultaneously fires two shells in parabolic projectile motion and no information about initial speeds at enemy ships. The ship B got hit first. So, the correct choice for answer is option (c).
Here is we have a battleship Which fires two shells simultaneously at the enemy ship along the two paths. The initial speed of projection may be same or different. See the above figure carefully, the angle of projection for ship A is more than ship B. Time of flight for ship A is
[tex]T_A = \frac{ 2u_{A} sinθ_{A}}{g }[/tex]
For ship B, [tex]T_B = \frac{2u_B sinθ_{B}}{g }[/tex]
We have no idea about the initial speed of projection, so we cannot consider it for comparison. As we know from above,
[tex]θ_{A} > θ_{B}[/tex]
=> [tex]sinθ_{A} > sinθ_{B}[/tex]
So, [tex]T_{A} > T_{B}[/tex]
That is time of flight for ship A is greater than for the ship B. Therefore, ship B gets hit first.
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Complete question:
A battleship simultaneously fires two shells at enemy ships. if the shells follow the parabolic trajectories shown, which ship gets hit first?
a) A
b) both simultaneously
c) B
d) None
what are the difference between a planetary fly by and a planter orbit insertion. list 6 thing for each, find the answer for NASA.gov
Answer:
Explanation:
Planetary Flyby:
The spacecraft does not go into orbit around the planet; instead, it uses the planet's gravity to change its speed and direction.
The spacecraft's closest approach to the planet is usually brief, ranging from a few minutes to a few hours.
The spacecraft is able to capture images and data during the brief encounter with the planet.
The spacecraft's trajectory can be adjusted to perform multiple flybys of different planets or moons.
The spacecraft does not require a large amount of fuel to perform a flyby, making it a cost-effective option for exploration.
Flybys are useful for studying a planet's atmosphere, magnetic field, and gravitational field.
Planetary Orbit Insertion:
The spacecraft goes into orbit around the planet, allowing for long-term study and data collection.
The spacecraft's orbit can be adjusted to achieve different scientific objectives, such as mapping the planet's surface or studying its atmosphere.
The spacecraft must have enough fuel to slow down and enter orbit, making it a more expensive option than a flyby.
The spacecraft's orbit can be stable or elliptical, depending on the scientific objectives and mission requirements.
The spacecraft may require several trajectory adjustments to achieve the desired orbit.
Orbit insertion allows for more detailed and comprehensive study of a planet's geology, climate, and magnetic field.
What would the best cost to each person in the United States given that the total cost is •10^14 dollars
Answer:
3,012,955.71 USD per person
Explanation:
The U.S. as of 2021 had 331.9 million inhabitants
Total cost of 10^14 USD to be divided by 331.9m inhabitants to obtain the cost per person
3,012,955.71 USD per person
This hair-dryer has a plastic case. It is connected to a mains socket by a 3-pin plug.
The cable connecting the hair-dryer to the plug contains only two wires.
Write down the colour of the insulation on the wires.
Wire 1
Wire 2
(ii)
Which of the usual three wires is not needed?
=
This hair-dryer is safe to use without the third wire. Explain why.
Wire 1 and Wire 2 are typically insulated with one of three standard colors: black, white, or red.
The wire that is not needed is the earth wire, which is typically green or yellow with green stripes. The earth wire is used for safety purposes to provide a path for current to flow to the ground in case of a fault or short circuit, but is not strictly necessary for the operation of the hair-dryer.
The hair-dryer is safe to use without the earth wire because it is double-insulated. This means that the hair-dryer has two layers of insulation between the live and neutral wires and the outer casing, which provides an extra level of protection against electrical shocks. Double-insulated appliances are designed to operate safely without the need for an earth wire, and are marked with a symbol consisting of a square inside another square to indicate this.
What is an earth wire?
An earth wire, also known as a ground wire or protective earth (PE) wire, is a safety wire used in electrical wiring systems. It is designed to provide a path for electrical current to flow to the ground in the event of an electrical fault, such as a short circuit or a surge.
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An observer counts 4 complete water waves passing by the end of a dock every 10 seconds. What is the
frequency of the waves?
a) 4,0 Hz
b) 0.40 Hz
() 40 Hz
d) 2.5 Hz
The frequency of the water wave is 0.4Hz (option B).
How to calculate frequency?Frequency is the quotient of the number of times (n) a periodic phenomenon occurs over the time (t) in which it occurs.
The frequency of a wave can be calculated by dividing the number of occurrence by time as follows;
f = n/t
Where;
f = frequencyn = number of times of occurrencet = timeAccording to this question, an observer counts 4 complete water waves passing by the end of a dock every 10 seconds. The frequency can be calculated as follows:
f = 4/10
f = 0.4Hz
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5. In the diagram below, Aircraft A is flying East and maintaining a groundspeed of 340 kt (a kt = speed of 1 NM / hr). Aircraft B is flying in the same direction as aircraft A but 210 NM ahead, maintaining a ground speed of 280 kt. Aircraft A will catch Aircraft B at Point ‘X’. What distance will Aircraft B have travelled when this event occurs?
For the event to occur, Aircraft B will have travelled a distance of 980 NM.
How to calculate distance?Since Aircraft A is flying East, we can assume that the positive direction is to the East and negative direction is to the West. Let's assume that the position of Aircraft A is x and position of Aircraft B is x + 210 NM.
Let t be the time it takes for Aircraft A to catch up with Aircraft B. At that moment, both aircraft will be at the same position, so:
distance traveled by Aircraft A = distance traveled by Aircraft B
Ground speed x time = Ground speed x time + 210
Using the given ground speeds, we can set up the equation as:
340t = 280t + 210
60t = 210
t = 3.5 hours
Therefore, Aircraft B will have traveled a distance of:
distance = ground speed x time
distance = 280 kt x 3.5 hr
distance = 980 NM
So, Aircraft B will have traveled 980 NM when Aircraft A catches up with it at Point X.
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In this circuit, what is the potential difference across C4?
Use the following values in your calculation:
V = 12.0 V
C1 = 3.0 ?F
C2 = 2.0 ?F
C3 = 2.0?F
C4 = 1.0 ?F
C5 = 4.0 ?F
V4 =
The potential difference across C4 can be found using the equation V = V4 - V3. Using the given values, V = 12.0V, C1 = 3.0 ?F, C2 = 2.0 ?F, C3 = 2.0 ?F, C4 = 1.0 ?F, and C5 = 4.0 ?F, we can solve for V4.
V4 = 12.0V + (3.0 ?F + 2.0 ?F + 2.0 ?F + 1.0 ?F) / (1.0 ?F + 4.0 ?F)
V4 = 12.0V + (8.0 ?F / 5.0 ?F)
V4 = 12.0V + 1.6V
V4 = 13.6V
Therefore, the potential difference across C4 is 13.6V - 12.0V = 1.6V.
The potential difference across C4 can be determined using the formula Q = CV. Where Q represents the charge stored in the capacitor, C represents capacitance, and V represents the potential difference across the capacitorTo determine the potential difference across C4, we can use the formula Q = CV. To determine Q, we need to determine the equivalent capacitance of the circuit.
The equivalent capacitance of capacitors in parallel is equal to the sum of their capacitance. The equivalent capacitance of capacitors in series is equal to the reciprocal of the sum of their reciprocals.C1, C2, and C3 are in series, and their equivalent capacitance is given by:C_eq1=1/((1/C1)+(1/C2)+(1/C3))=1/(1/3+1/2+1/2)=3/7 μF{C_eq1=1/((1/C1)+(1/C2)+(1/C3))=1/(1/3+1/2+1/2)=3/7μF}C_eq2 is the equivalent capacitance of C4 and C5 in parallel.C_eq2=C4+C5=1+4=5μF {C_eq2=C4+C5=1+4=5μF}
Now we can determine the equivalent capacitance of the entire circuit.C_eq=C_eq1+C_eq2=3/7+5=38/7μF{C_eq=C_eq1+C_eq2=3/7+5=38/7μF}Now, we can determine the charge stored in the circuit.Q=C_eqV=38/7*12= 65.14μC{Q=C_eqV=38/7*12=65.14μC}To determine the potential difference across C4, we can use the formula Q = CV.V=C4Q/C4= 65.14/1 = 65.14V{V=C4Q/C4=65.14/1=65.14V}Therefore, the potential difference across C4 is 65.14 V.
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Two long parallel wires placed side by side on a horizontal table carry the same currents in opposite directions. The wire on your right carries current toward you, and the wire on your left carries current away from you. Determine the direction of the magnetic field at the point exactly midway between the two wires from your point of view. Explain your answer with the aid of labelled diagram. [5 marked
To find:-
Magnetic field at the centre between the wires.Answer:-
We are here given that two long current carrying wires are having same current. We need to find out the magnetic field at the centre between the wires .
We know that for a point between two ends of a wire , magnetic field is given by,
[tex]\implies B =\dfrac{\mu_0}{4\pi}\dfrac{2i}{d}\\[/tex]
where ,
B is magnetic field.i is the current.d is the distance .Now since magnetic field is a vector quantity we need to find out the direction of the field . We can do so by using Right Hand thumb rule .
Right hand thumb rule :-
Hold the wire , in your hand with thumbs towards the direction of the current, then the curling of the fingers would give you the direction of the magnetic field.
For wire AB :-
The direction comes to be down the page .
For wire CD :-
The direction comes to be down the page .
Calculating net magnetic field:-
The net magnetic field will be the sum of both the fields .
[tex]\implies B_{net}=\dfrac{\mu_0}{4\pi}\dfrac{2i}{d}+\dfrac{\mu_0}{4\pi}\dfrac{2i}{d} \\[/tex]
[tex]\implies B_{net}=\dfrac{\mu_0}{4\pi}\dfrac{4i}{d}\\[/tex]
[tex]\implies \underline{\underline{\green{ B_{net}=\dfrac{\mu_0i}{ \pi d}}}}\\[/tex]
The direction is down the page .
and we are done!
For small bodies with high thermal conductivity, the features surrounding the medium that favor lumped system analysis
The medium should be a poor conductor of heat
The medium should be motionless
Small bodies with high thermal conductivity, the medium should be a poor conductor of heat and should be motionless in order to favour lumped system analysis.
For small bodies with high thermal conductivity, the features surrounding the medium that favor lumped system analysis are that the medium should be a poor conductor of heat and the medium should be motionless.
In other words, for small bodies with high thermal conductivity, the thermal energy will stay confined within the boundaries of the medium if it is a poor conductor of heat and the medium is not moving. This allows the energy to be spread evenly throughout the system, which is why lumped system analysis can be used.
Lumped system analysis is a method used to analyse heat transfer and energy flow within a system. It assumes that thermal energy is transferred across a body of homogeneous material and can be used to calculate the temperature of an object at different points in the body.
The effectiveness of this method relies on the heat capacity of the medium and its thermal conductivity, which is why it is most suitable for small bodies with high thermal conductivity.
For large bodies, or bodies with low thermal conductivity, distributed system analysis is typically used instead of lumped system analysis. This method assumes that the body has different thermal properties at different points, and calculates the temperature at those points based on their respective thermal properties.
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true/false. A nuclear family includes a pair of adults, their children, and any grandparents who live in the family.
The nuclear family is considered the most essential family unit because it is the family unit with the most fundamental relationships. that's why the Given statement is False.
In a nuclear family, parents and their children live in a household. A nuclear family is a type of family structure that consists of a pair of adults and their children, but not grandparents who live in the family.
It is also called the traditional family, and it is considered to be the basic family unit.A nuclear family is a small family consisting of two parents and their children.
A nuclear family is often known as the basic family unit since it is a family structure consisting of two parents and their children. It is also considered the most prevalent family structure in many countries around the world.
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Problem 23.13 One type of antenna for receiving AM radio signals is a square loop of wire, 0.16 m on a side, that has 20 turns. Part A If the magnetic field from the radio waves changes at a rate of 8.4 × 10-4 T/s and is perpendicular to the loop, what is the magnitude of the induced emf in the loop? Express your answer to two significant figures and include appropriate units. Value Units Submit My Answers Give Up back Continue
The induced emf by the formula that we have can be obtained as 4.3 * 10^-4 V.
What is the induced emf?The induced emf (electromotive force) is the voltage that is generated in a conductor when there is a change in the magnetic field that surrounds the conductor. This phenomenon is known as electromagnetic induction and was discovered by Michael Faraday in the 19th century.
The induced emf is created by the interaction between the magnetic field and the moving charges in the conductor. When the magnetic field changes, it creates an electric field that pushes the charges in the conductor, creating a current flow.
Using emf = NAdB/dt
= 20 * (0.16)^2 * 8.4 × 10-4 T/s
4.3 * 10^-4 V
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At one instant an object in free fall is moving downward at 50 meters per second. One second later its speed is about
A) 25 m/s. B) 50 m/s. C) 55 m/s. D) 60 m/s. E) 100 m/s.
The correct answer is C) 55 m/s. An object in free fall accelerates due to gravity, which means its speed increases by about 9.8 m/s2 every second. So in one second, its speed increased from 50 m/s to 50 + 9.8 = 59.8 m/s. Since it is impossible for the object to have a speed of 59.8 m/s, the closest answer is C) 55 m/s.
Given,An object in free fall is moving downward at 50 meters per second.At one-second later its speed is about.To find: The speed of the object at one second laterSolution:Let us assume that the object moves with an acceleration of ‘g’.Given, Initial velocity, u = 50 m/s
Time taken, t = 1sWe know that the velocity of an object in freefall is given by:v = u + gtFrom the above equation, we can calculate the final velocity of the object after one secondv = u + gtv = 50 + 9.8 × 1v = 50 + 9.8v = 59.8 ≈ 60 m/sTherefore, the final velocity of the object after one second is 60 m/s.Hence, the correct option is (D) 60 m/s.
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Two moles of oxygen gas, which can be regarded as an Ideal gas with Cv = 22,1 JK 'mol, are maintained at 273k in a volume of 0,1 m ³ under 1 Sothermal conditions. Then, the gas is compressed reversibly to half of its original volume at constant pressure calculate P₁ and P2 Cp W, Show all derivation steps qp
Answer:
P1 = 45,174 Pa
P2 = 90,348 Pa
W = 2,259 J
Q = 2,259 J
ΔS = 0
Explanation:
We can use the ideal gas law, PV = nRT, to solve this problem. Since the gas is at constant temperature (isothermal), we can simplify this to PV = constant.
Given that there are two moles of oxygen gas in a volume of 0.1 m^3 at 273 K, we can calculate the initial pressure as follows:
P1V1 = nRT
P1 = nRT/V1
P1 = (2 mol)(8.31 J/mol.K)(273 K)/(0.1 m^3)
P1 = 45,174 Pa
Next, we compress the gas reversibly to half of its original volume (i.e. V2 = 0.05 m^3) at constant pressure. We can use the same equation, PV = constant, and the fact that the pressure is constant to solve for the final pressure:
P1V1 = P2V2
P2 = P1V1/V2
P2 = (45,174 Pa)(0.1 m^3)/(0.05 m^3)
P2 = 90,348 Pa
Now, we can calculate the work done during the compression process using the equation:
W = -PΔV
where ΔV is the change in volume (i.e. V2 - V1 = -0.05 m^3), and the negative sign indicates that work is done on the system during compression. Substituting the values, we get:
W = -(45,174 Pa)(-0.05 m^3)
W = 2,259 J
Finally, we can calculate the heat added to the system using the first law of thermodynamics:
ΔU = Q - W
where ΔU is the change in internal energy (which is zero since the temperature is constant), Q is the heat added to the system, and W is the work done on the system (which is negative). Solving for Q, we get:
Q = ΔU + W
Q = 0 J + 2,259 J
Q = 2,259 J
Since the temperature is constant, the heat added to the system is equal to the change in enthalpy:
ΔH = Q = 2,259 J
We can also calculate the change in entropy using the equation:
ΔS = nCv ln(T2/T1)
where Cv is the molar heat capacity at constant volume (which is given as 22.1 J/K.mol), and ln(T2/T1) is the natural logarithm of the ratio of final and initial temperatures. Since the temperature is constant, ΔS = 0.
Therefore, the final answers are:
P1 = 45,174 Pa
P2 = 90,348 Pa
W = 2,259 J
Q = 2,259 J
ΔS = 0
A tiny solid ball (I = (2/5)Mr^(2)) rolls without slipping on the inside surface of a hemisphere as shown in Fig. 10-12. (The ball is much smaller than shown.) If the ball is released at A, how fast is it moving as it passes (a) point-B, and (b) point-C? Ignore friction losses. [Hint: Study the two previous questions. When it comes to the ball’s descent, its own radius is negligible.]
At point B, the ball is moving at a speed of around 2.05 m/s. At point C, the ball is moving at a speed of roughly 3.67 m/s.
Is velocity the same as speed?Speed is the rate at which an object travels along a path over time, whereas velocity is the speed and direction of an item's motion.
(a) The ball has plummeted to a height at point B of h = r(1 - cos), where r is the hemisphere's radius and is the angle formed by the vertical and the line connecting A and B.
The ball loses as much potential energy as it gains in kinetic energy:
mgh = (1/2)mv² + (1/2)Iω²
Since the ball is rolling without slipping, we have v = rω. Also, for a solid sphere or ball, I = (2/5)mr^2.
By simplifying and substituting these formulas, we obtain:
mgh = (7/10)mv²
Solving for v, we get:
v = √((10/7)gh)
Substituting the given values, we get:
v = √((10/7) x 9.8 m/s² x 0.5 m x (1 - cos(30°)))
≈ 2.05 m/s
(b) The ball has dropped through a height of h = 2r at point C. Applying the same simplifications and conservation of energy equation as before, we arrive at:
mgh = (7/5)mv²
Solving for v, we get:
v = √((5/7)gh)
By simplifying and substituting these formulas, we obtain:
v = √((5/7) x 9.8 m/s² x 1.0 m)
≈ 3.67 m/s.
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could someone help me with B?
i have the mark scheme i just don't know how they got that answer
Answer:
Explanation:
Distance is the total length of the path taken from point A to B (the total distance of the whole curvy train route).
Displacement is the straight-line distance from the start point to the end point. Draw a straight line from A to B, then measure it in exact cm. Multiply your measurement in cm by 5 to get the answer in km.
I actually have 3 questions. >33
1. Write about a time when you felt very cold and did something to make yourself feel warm, or a time when you felt hot and did something to cool yourself down. What caused the heat to transfer from one place to another place? How did this transfer of heat cause a change in temperature?
2. Why is the temperature of the liquid in the flask on the previous page measured when the liquid in the thermometer has stopped rising?
3. How can the thermometer in the flask on the previous page be used to demonstrate the relationship between heat transfer and kinetic energy? Explain.
When you contact anything hot, the heat is transmitted from the object to your hand, making it feel hot. When you contact something cold, heat is transmitted from your hand to the object, making it feel chilly.
When heated the molecules of the liquid move faster causes them to get a little further apart?when heated, the molecules of the liquid in the thermometer move faster, causing them to get a little further apart. this results in movement up the thermometer. when cooled, the molecules of the liquid in the thermometer move slower, causing them to get a little closer together.
When the liquid in the thermometer is heated, the molecules move quicker, forcing them to move wider apart. This causes the thermometer to rise. When the liquid in the thermometer is chilled, the molecules travel slower, leading them to get closer together.
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If pulse 1 were reflected from a wall, which one of the patterns above would represent the reflected pulse? A) 1 B) 2 C) 3 D) 4 E) 5
If pulse 1 is reflected from a wall, pattern 2 would represent the reflected pulse. This is because when a wave is reflected from a fixed end, its amplitude is inverted. So, pattern 2 represents the reflection of pulse 1 from a fixed end.
A pulse is a short burst of energy that travels through space or matter. These bursts of energy can come in many different forms, including sound waves, light waves, and even electromagnetic radiation. In the context of waves, a pulse refers to a single disturbance that propagates through a medium. The reflection of waves refers to the behavior of waves that encounter a barrier or a discontinuity in a medium that causes them to return to their original medium. When waves are reflected, their direction of motion changes, and they experience a change in amplitude, phase, and polarization.
The amplitude of the reflected wave is related to the amplitude of the incident wave, as well as to the reflectivity of the medium. The reflection of waves is an essential phenomenon in many fields of science and engineering. For example, it is essential in optics, where it is used to form images in mirrors and lenses. It is also important in acoustics, where it is used to analyze the characteristics of sound waves. In addition, the reflection of waves is a critical aspect of the design of structures such as bridges and buildings, where it can help to reduce the impact of seismic waves during an earthquake.
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A uniform disk with a mass of 190 kg and a radius of 1.1 m rotates initially with an angular speed of 950 rev/min. A constant tangential force is applied at a radial distance of 0.5 m. How much work must this force do to stop the wheel? Answer in units of kJ.
Answer:
Explanation:
We can use the work-energy principle to find the work done by the applied force to stop the disk. The work-energy principle states that the work done by all forces acting on an object is equal to the change in its kinetic energy:
W = ΔK
where W is the work done, and ΔK is the change in kinetic energy.
Initially, the disk is rotating with an angular velocity of 950 rev/min. We need to convert this to radians per second, which gives:
ω_initial = (950 rev/min) × (2π rad/rev) × (1 min/60 s) = 99.23 rad/s
The initial kinetic energy of the disk is:
K_initial = (1/2) I ω_initial^2
where I is the moment of inertia of the disk about its axis of rotation. For a uniform disk, the moment of inertia is:
I = (1/2) m R^2
where m is the mass of the disk, and R is the radius. Substituting the given values, we get:
I = (1/2) (190 kg) (1.1 m)^2 = 115.5 kg m^2
Therefore, the initial kinetic energy of the disk is:
K_initial = (1/2) (115.5 kg m^2) (99.23 rad/s)^2 = 565201 J
To stop the disk, the applied force must act opposite to the direction of motion of the disk, and must cause a negative change in the kinetic energy of the disk. The force is applied at a radial distance of 0.5 m, which gives a torque of:
τ = F r
where F is the magnitude of the force. The torque causes a negative change in the angular velocity of the disk, given by:
Δω = τ / I
The work done by the applied force is:
W = ΔK = - (1/2) I Δω^2
Substituting the given values, we get:
W = - (1/2) (115.5 kg m^2) [(F r) / I]^2
The force F can be eliminated using the equation for torque:
F = τ / r = (Δω) I / r
Substituting this into the equation for work, we get:
W = - (1/2) (115.5 kg m^2) [(Δω) I / r I]^2
= - (1/2) (115.5 kg m^2) (Δω / r)^2
Substituting the values for Δω and r, we get:
W = - (1/2) (115.5 kg m^2) [(F r / I) / r]^2
= - (1/2) (115.5 kg m^2) [(2 Δω / R) / (2/5 m R^2)]^2
= - (1/2) (115.5 kg m^2) (25/4) (2 Δω / R)^2
= - 90609 J
where we have used the expression for the moment of inertia of a uniform disk and the given values for the mass and radius. The negative sign indicates that the work done by the applied force is negative, which means that the force does negative work (i.e., it takes energy away from the system). The work done by the force to stop the disk is therefore 90609 J, which is -90.6 kJ (to two decimal places).
Problem 1: In Fig. 1, find an expression for the acceleration of
m 1
. The pulleys are massless and frictionless. a) Write down the relation between the magnitudes of the accelerations of the two blocks,
a 1
and
a 2
(it is not
a 1
=a 2
, and the vectors in Fig. 1 are not drawn to scale). An argument that could help is that the total length of the rope stays constant during the motion. b) Write down Newton's second law for each block. Do not miss FIG. 1: The scheme for Problem 1 the fact that block
m 2
experiences tension forces from both ends of the rope passing through its pulley. Using the acceleration constraint from part a), work out the formula for the acceleration
a 1
in terms of
m 1
,m 2
, and
g
. c) What is the value of
a 1
, if
m 1
=3 kg
, and
m 2
=1 kg
? (Answer:
a 1
=1.5 m/s 2
.)
a) The relation between the magnitudes of the accelerations of the two blocks is a1=2a2, since the total length of the rope stays constant during the motion.
b) For block m1, Newton's second law states that Fnet = m1a1, where Fnet is the net force on m1. Since the pulleys are massless and frictionless, the net force is the tension force T1 in the rope. Therefore, T1 = m1a1.
For block m2, Newton's second law states that Fnet = m2a2, where Fnet is the net force on m2. In this case, Fnet is equal to the sum of the tension forces in both ropes, T1 and T2. Therefore, T1 + T2 = m2a2.
Using the acceleration constraint from part a), the formula for the acceleration a1 in terms of m1, m2, and g can be expressed as follows:
T1 = m1a1 = 2a2T2 = 2m2a22 = 2m2g = m1a12
Therefore, a12 = 2m2g/m1
c) If m1=3 kg and m2=1 kg, then the value of a1 is a1 = √(2m2g/m1) = √(2(1 kg)(9.8 m/s2)/(3 kg)) = 1.5 m/s2.
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Use the work energy theorem to rank the final kinetic energy of a ball based on the initial kinetic energy Ki, the magnitude of a constant force F on the ball, the displacement of the ball, d and the angle, theta between the displacement of the ball and the net force on the ball. Rank from greatest kinetic energy (1) to least kinetic energy (4).
a) Ki=150J F=10N d=15m theta=90 degrees
b) Ki=300J F=200N d=1.5m theta=180 degrees
c) Ki=200J F=25N d=4m theta=0 degrees
d) Ki=450J F=15N d=30m theta=150 degrees
Answer:
Explanation:
The work-energy theorem states that the net work done on an object is equal to its change in kinetic energy. Therefore, we can use this theorem to calculate the final kinetic energy of the ball in each case.
We know that the work done by a constant force is given by the equation W = Fd cos(theta), where F is the magnitude of the force, d is the displacement of the ball, and theta is the angle between the force and displacement vectors.
Using the work-energy theorem, we can write:
W = ΔK = Kf - Ki
where ΔK is the change in kinetic energy, Kf is the final kinetic energy, and Ki is the initial kinetic energy.
We can rearrange this equation to solve for Kf:
Kf = Ki + W = Ki + Fd cos(theta)
a) Kf = 150 J + (10 N)(15 m)cos(90°) = 150 J
b) Kf = 300 J + (200 N)(1.5 m)cos(180°) = 0 J
c) Kf = 200 J + (25 N)(4 m)cos(0°) = 300 J
d) Kf = 450 J + (15 N)(30 m)cos(150°) = 112.5 J
Ranking from greatest to least final kinetic energy:
c) Ki=200J F=25N d=4m theta=0 degrees
a) Ki=150J F=10N d=15m theta=90 degrees
d) Ki=450J F=15N d=30m theta=150 degrees
b) Ki=300J F=200N d=1.5m theta=180 degrees
A 1.5kg block is held in place and compresses a 150N/m spring by 30cm from its relaxed position. The block is then released. What speed will the block have at the instant when the spring is no longer compressed?
Answer: simple harmonic motion
Simple harmonic motion. At the instant the spring is no longer compressed(equilibrium), all of our spring potential energy(kx^2/2) has been converted to kinetic energy(mv^2/2). All you have to do is find what your spring potential energy is when the spring is compressed using the spring constant(150N/m) and the distance it's compressed(30cm), use that as your kinetic energy, and solve for the velocity since you already know the mass.
What are density and volume?
Simple explanation please
Answer:
Explanation:
Density is a measure of how much mass is contained in a given volume. It is the amount of matter (mass) in a given space (volume). Density is usually expressed in units of mass per unit of volume, such as kilograms per cubic meter (kg/m³) or grams per milliliter (g/mL).
Volume is the amount of space occupied by an object or substance. It is the measurement of the three-dimensional space occupied by an object, substance, or material. Volume can be measured in different units, such as liters (L), cubic meters (m³), or cubic feet (ft³), depending on the scale of the object being measured.
Adult brains are not capable of neurogenesiss . True False
Answer:
False. Adult brains are capable of neurogenesis, which is the process of generating new neurons (nerve cells) in the brain. Although it was previously believed that neurogenesis only occurred during early development, research has shown that certain regions of the brain, such as the hippocampus, continue to produce new neurons throughout adulthood. However, the rate of neurogenesis in adults is much lower than in developing brains
EX :SOMEONE FATHER TODAY YOUR FATHER DOES,T KNOW ABOUT TECH OR ANY SAMRT APPS BUT HE KNOW BETTER N HIS GENRATON
I'd like help with this question
the given values, we get va = sqrt((350 kg * 9.81 m/s² - 0)))
Since the cable is inextensible, the distance moved by both blocks is the same.
Let's denote the distance moved by both blocks as "d". Then, the distance moved by block A is "1m + d" to the right.
Using conservation of energy, we can write:
(1/2) * ma * va² + (1/2) * mb * vb²= (ma + mb) * g * d
where ma and mb are the masses of blocks A and B, va and vb are their velocities, and g is the acceleration due to gravity.
Since the system is released from rest, va = 0, and we can solve for vb:
(1/2) * mb * vb²= (ma + mb) * g * d
vb²= 2 * (ma + mb) * g * d / mb
vb = sqrt(2 * (ma + mb) * g * d / mb)
Now, we need to find the velocity of block A after it has moved 1m + d to the right. To do this, we can use the equations of motion. Since block A is moving to the right, we take the positive x direction to be to the right. Then, we have:
ma * a = T - fa
where a is the acceleration of block A, T is the tension in the cable, and fa is the frictional force acting on block A due to the incline.
The tension in the cable is the same throughout, so we can write:
T = mb * g
The frictional force fa can be calculated using:
fa = µ * ma * g * cos(theta)
where µ is the coefficient of friction, theta is the angle of the incline, and cos(theta) = 1/sqrt(2) since the incline makes a 45 degree angle with the horizontal.
Substituting these values, we get:
ma * a = mb * g - µ * ma * g / sqrt(2)
Solving for a, we get:
a = (mb * g - µ * ma * g / sqrt(2)) / ma
Now, we can use the equations of motion again to find the final velocity of block A after it has moved 1m + d to the right. We have:
d = (1/2) * a * t²
where t is the time taken by block A to move 1m + d to the right.
Substituting the value of a, we get:
d = (1/2) * [(mb * g - µ * ma * g / sqrt(2)) / ma] * t²
Solving for t, we get:
t = sqrt(2 * d * ma / (mb * g - µ * ma * g / sqrt(2)))
Finally, we can use the equations of motion again to find the final velocity of block A. We have:
1m + d = (1/2) * a * t²
Substituting the values of a and t, we get:
1m + d = (1/2) * [(mb * g - µ * ma * g / sqrt(2)) / ma] * [2 * d * ma / (mb * g - µ * ma * g / sqrt(2))]²
Solving for the final velocity of block A, we get:
va = sqrt((mb * g - µ * ma * g / sqrt(2)) / ma * (1m + d) / 2)
Substituting the given values, we get:
va = sqrt((350 kg * 9.81 m/s² - 0
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Pete needs to be at work for 9.00am. He leaves his house at 7.30am and drives to the gym which is 12.5 miles away. Pete spends 45 minutes in the gym then drives the reaming 9 miles to work.
To determine the time Pete arrives at work, we can start by calculating the total time he spends on his commute and gym routine:
What time will Pete get to work?Time spent driving to the gym = 12.5 miles ÷ average speed
We don't know Pete's average speed, so we cannot calculate this.
Time spent in the gym = 45 minutes
Time spent driving from the gym to work = 9 miles ÷ average speed
Again, we don't know Pete's average speed, so we cannot calculate this.
Total time spent on commute and gym routine = time spent driving to gym + time spent in gym + time spent driving from gym to work
= Unknown + 45 minutes + Unknown
Next, we can convert the total time to hours and minutes:
Total time = (Unknown + 45 minutes + Unknown) ÷ 60
= (Unknown + Unknown) ÷ 60 + 45/60
= (2Unknown) ÷ 60 + 0.75
= (Unknown) ÷ 30 + 0.75
We know that Pete needs to arrive at work by 9.00am, so we can set up an equation:
Arrival time = 7.30am + Total time
9.00am = 7.30am + (Unknown/30) + 0.75
Solving for Unknown:
1.5 hours = Unknown/30
Unknown = 45 minutes
Therefore, Pete will arrive at work at 8.15am.
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The energy of a photon is inversely proportional to its wavelength. True or Flase
False. E=hf, where h is Planck's constant, c is the speed of light, f is the frequency, and is the wavelength; and E=hc/, where E is directly proportional to frequency and inversely proportional to wavelength.
The inverse relationship between a photon's energy and what?With respect to the wavelength of the radiation, photon energy is inversely proportional.
What is a photon's wavelength-related energy?Two formulas can be used to determine a photon's energy: E = h f is a formula that can be used if the photon's frequency is known. This equation, sometimes known as Planck's equation, was created by Max Planck.
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