Answer:
Newton’s first law of motion states that there must be a cause—which is a net external force—for there to be any change in velocity, either a change in magnitude or direction. An object sliding across a table or floor slows down due to the net force of friction acting on the object.
Explanation:
The electric motor of an elevator(lift) uses 630kJ of electric energy when raising the elevator and passengers, of total mass 12,500N, through a vertical height of 29m.Calculate the efficiency of the elevator. pppppplease need helpp willl markk the brrainliest
Answer:
Efficiency = 0.575 = 57.5%
Explanation:
First, we will calculate the output energy of the elevator, which is equal to the potential energy acquired by the load.
[tex]O = Potential\ Energy\\O = mgh[/tex]
where,
O = Output = ?
mg = W = Weight = 12500 N
h = height = 29 m
Therefore,
[tex]O = (12500\ N)(29\ m) \\O = 362500\ J = 362.5\ KJ[/tex]
The input is given as:
I = 630 KJ
Thus the efficiency will be:
[tex]Efficiency = \frac{O}{I} = \frac{362.5\ KJ}{630\ KJ}\\\\[/tex]
Efficiency = 0.575 = 57.5%
Si se desea construir un circuito con poca resistencia se debe colocar: En serie Mixto Paralelo Ninguna de las anteriores
Answer:
Parallel combination
Explanation:
When the two resistances are connected in parallel then the equivalent resistance is
[tex]\frac{1}{R}=\frac{1}{R'}+\frac{1}{R''}[/tex]
To get the minimum resistance of a circuit, the circuit components should be connected in parallel combination.
In the parallel combination, the voltage across each resistor is same and the current is divided in every resistance according to the resistances.
How does the "lollipop moment", exemplify for us the opportunity we all have to exercise leadership on a normal everyday basis?
Answer:
WHat do you mean by that
Explanation:
I dont get what you re asking
Who was Sir Isaac Newton? Be sure to explain in your own words.
Answer:
the person who invented gravity
Explanation:
newton was a mathmaticians when one day an apple fell on him. he had the idea to name the force gravity. While he "made" gravity he made other important laws the 3 newton laws of physics
Answer:
Issac Newton was around in the 1600s and early 1700s and is a very important mathematician and invented calculus.
Explanation:
The sun is located in
the Crab Nebula.
the Andromeda Nebula.
the Milky Way Galaxy.
the Snickers Galaxy.
Answer:
The sun is located in the Milky Way Galaxy.
2. 2. A drawing that shows the outline of an object is called
what happens when a candle burns?
a) oxygen is used up
b) nitrogen is used up
c) hydrogen is produced
d) carbon dioxide is consumed
Answer:
oxygen is used up is the answer
Explanation:
These vaporized molecules are drawn up into the flame, where they react with oxygen from the air to create heat, light, water vapor (H2O) and carbon dioxide (CO2).
Question 2 of 10
A wave has a wavelength of 0.05 m and a wave speed of 10 m/s. What is the
frequency of the wave?
O A. 5.0 Hz
B. 200 Hz
C. 2.0 Hz
O D. 0.50 Hz
Explanation:
everything can be found in the picture
What is the answer to this question?
Answer:
Explanation:
In a velocity/time (aka acceleration) graph, the slope of a line indicates the value of the acceleration in m/s/s. Acceleration is the change in velocity over the change in time. From 0 - 2 seconds, there is no change in velocity, so the acceleration during this interval is 0 (which is the same as the slope of the line). From 2 - 4 seconds, the slope of the line is -2, so the acceleration during the time interval from 2 to 4 seconds is -2 (negative because David is slowing down but is still going the same direction: to the right).
PLEASE HELP WITH THIS QUESTION
The reason you should always wear your seatbelt in a moving car
A. Newton's 1st law
B. Newton's 2nd law
C. Newton's 3rd law
A sled drops 20 mts in height on a hill. The rider is going 20 m/s at the bottom of the hill. Where can you find kinetic and potential energy? In which moments?
Explanation:
Potential energy is the energy occupied by an object or substance due to its position.
For example, a sled drops 20 meters in height on a hill shows that a decrease in height is taking place.
Hence, potential energy is involved there.
Kinetic energy is the energy acquired by an object due to its motion.
For example, a rider is going 20 m/s at the bottom of the hill shows that rider is in motion due to which it has kinetic energy.
El peso(w) de una persona en la Tierra es 550N. Determinar la masa (m) de la persona y el peso (w) de la misma en la Luna
The question is: The weight (w) of a person on Earth is 550N. Determine the mass (m) of the person and the weight (w) of the person on the Moon.
Answer: The mass (m) of the person is 550 N and the weight (w) of the person on the Moon is 891 kg.
Explanation:
Given: Mass = 550 N
When a person moves towards moon then its mass will remain the same but there will occur change in its weight because the acceleration due to gravity on moon is different than that on Earth.
Therefore, formula used to calculate the weight of person on moon is as follows.
[tex]W = m \times g_{m}[/tex]
where,
m = mass
[tex]g_{m}[/tex] = acceleration due to gravity on moon = 1.62 [tex]m/s^{2}[/tex]
Substitute the values into above formula as follows.
[tex]W = m \times g_{m}\\= 550 N \times 1.62 m/s^{2}\\ (1 N = 1 kg \times m/s^{2})\\= 891 kg[/tex]
Thus, we can conclude that the mass (m) of the person is 550 N and the weight (w) of the person on the Moon is 891 kg.
Two forces that make up 3rd law of motion can: 1)Act on the same object 2)do not act on same time 3)Act on different objects 4)Do not act oppositely
Answer:
3) Act on different objects
Explanation:
Newton's third law of motion states that for every action there is an equal and opposite reaction.
Action-reaction force pairs make it possible for fishes to swim, birds to fly, cars to move, etc.
Basically, action-reaction force pairs are characterized by the following statements;
I. The forces are the same type such as magnetic force, contact force or gravitational force.
II. The forces are equal in magnitude but opposite in direction.
III. They act up on two different bodies.
Hence, the two forces that make up 3rd law of motion can act on different objects.
For example, while driving down the road, a bug strikes the windshield of a vehicle (Action) and makes a quite obvious mess in front of the face of the driver of the vehicle (Reaction) i.e the bug hit the vehicle and the vehicle hits the bug.
Mike roller skates with a constant speed of 10 miles per hour. How long will he take to travel a distance of 15 miles.
Answer:
So every hour he makes 10 miles. So he would take 1 and a half hours to go to Mcdonalds 15 miles away.
Explanation:
[tex]\huge\boxed{{\textsf{90 minutes}}}[/tex]
We know that Mike's speed is [tex]\dfrac{10\ \text{miles}}{60\ \text{minutes}}[/tex] since there are [tex]60[/tex] minutes in an hour, and we know that MIke needs to travel [tex]15[/tex] miles. We'll model this using fractions:
[tex]\dfrac{10\ \text{miles}}{60\ \text{minutes}}=\dfrac{15\ \text{miles}}{x\ \text{minutes}}[/tex]
We can see that there is a [tex]2:3[/tex] ratio here, so we'll divide the left fraction by [tex]2[/tex] and multiply it by [tex]3[/tex] to get the right fraction.
[tex]\dfrac{10}{60}\Rightarrow\dfrac{5}{30}\Rightarrow\dfrac{15\ \text{miles}}{\boxed{90\ \text{minutes}}}[/tex]
How to solve the equation of power ?
Answer:
OK HERE
Explanation:
When raising a power to a power in an exponential expression, you find the new power by multiplying the two powers together. For example, in the following expression, x to the power of 3 is being raised to the power of 6, and so you would multiply 3 and 6 to find the new power.
Magali exerts a force of 4.5 N to slide her Blackberry across the table (so she can hide it from Hina!). If she does 2.7 J of work in the process, how far has the Blackberry moved?
Work is equal to the magnitude of the force multiplied by the displacement x. Assuming Magali is pushing the phone, so that the force and displacement point in the same direction, then the work done is positive, and
2.7 J = (4.5 N) x ==> x = (2.7 J) / (4.5 N) = 0.60 m
Even if she was pulling the phone instead, the displacement would be the same, but the work done would be negative and the force would point in the opposite direction, thus also having a negative sign:
-2.7 J = (-4.5 N) x ==> x = 0.60 m
If a wire with current 5.0A has 12 coulombs of charge pass through it how much has passed
Answer:
2.4 secs.
Explanation:
Current (A) = Charge (coulomb)/Time(sec)
We are looking for time. So:
Time (sec) = Charge (coulomb)/Current (A)
↓
12coulombs/5.0A = 2.4 secs
An object with a mass of 20 kg has a net force of 80 N acting on it. What is the acceleration of the object?
Answer:
the answer is 4m/ s²
hope this helps love!! <3
Which of the following types of stars is cooler that an orange main sequence?
Answer:
Not sure but, I think C
Hopefully this helps
converts light energy to electrical energy
this electric current produced can be stored in another rechargeable cell.
If the collector of the cell is covered the voltage is higher
The current shown is real current
All of the above
None of the above
Answer:
If the collector of the cell is covered, the voltage is higher
Explanation:
The collector of the a passive, active, or photovoltaic (PV) solar cell is the device that takes the Sun's energy by the absorption of the Sun's radiation which is then transformed into electricity and heat. The ability to absorb the Sun's energy is given by the material type and the coating of solar collector
Therefore, the device requires access to energy from Sunlight to get the energy which can be stored in a rechargeable cell and well the collector's cell is covered, access to Sunlight is denied and therefore energy is not supplied to the cells and current is not generated and there is no flow of electricity and the voltage in the circuit is lower or there is no voltage in the circuit
The statement which is wrong about the solar cell is therefore, that if the collector of the cell is covered, the voltage is higher
What is meant by electric current?
Explanation:
the electric current is ratio of electric poer to the voltage
Which is not true of friction? A. Causes wear and tear of the surfaces B. Helps us to fall easily on roads C. Produces heat D. Produces light E. Stops bodies when they move over each other.
Answer:
B.
Hope this helps
Cuanto cambia la entropía de 0.50 kg de vapor de mercurio [Lv: 2.7 x 10⁵ j/kg ] al calentarse en su punto de ebullición de 357° C?
Answer:
La entropía del vapor de mercurio cambia en 214.235 joules por Kelvin.
Explanation:
Por definición de entropía ([tex]S[/tex]), medida en joules por Kelvin, tenemos la siguiente expresión:
[tex]dS = \frac{\delta Q}{T}[/tex] (1)
Donde:
[tex]Q[/tex] - Ganancia de calor, en joules.
[tex]T[/tex] - Temperatura del sistema, en Kelvin.
Ampliamos (1) por la definición de calor latente:
[tex]dS = \frac{L_{v}}{T}\cdot dm[/tex] (1b)
Donde:
[tex]m[/tex] - Masa del sistema, en kilogramos.
[tex]L_{v}[/tex] - Calor latente de vaporización, en joules
Puesto que no existe cambio en la temperatura durante el proceso de vaporización, transformamos la expresión diferencial en expresión de diferencia, es decir:
[tex]\Delta S = \frac{\Delta m \cdot L_{v}}{T}[/tex]
Como vemos, el cambio de la entropía asociada al cambio de fase del mercurio es directamente proporcional a la masa del sistema. Si tenemos que [tex]m = 0.50\,kg[/tex],[tex]L_{v} = 2.7\times 10^{5}\,\frac{J}{kg}[/tex] and [tex]T = 630.15\,K[/tex], entonces el cambio de entropía es:
[tex]\Delta S = \frac{(0.50\,kg)\cdot \left(2.7\times 10^{5}\,\frac{J}{kg} \right)}{630.15\,K}[/tex]
[tex]\Delta S = 214.235 \,\frac{J}{K}[/tex]
La entropía del vapor de mercurio cambia en 214.235 joules por Kelvin.
What is latent heat?
A.
energy released or absorbed to change the kinetic energy of a substance
B.
energy released or absorbed to change the pressure of a substance
C.
energy released or absorbed to change the temperature of a substance
D.
energy released or absorbed to change the phase of a substance
a. An object takes 5 s to reach the
ground from a height of 5 m on a
planet. What is the value of g on the
planet?
Ans: 0.4 m/s2
Answer:
g = 0.4 m/s²
Explanation:
Given the following data;
Height = 5 meters
Time = 5 seconds
To find the acceleration due to gravity (g) on the planet;
Mathematically, the maximum height of an object is given by the formula;
H = ½gt²
Where;
H is the height measured in meters.
g is the acceleration due to gravity.
t is time measured in seconds.
Substituting into the formula, we have;
5 = ½ * g * 5²
5 = 0.5 * g * 25
5 = 12.5 * g
g = 5/12.5
g = 0.4 m/s²
12 Write a difference between FPS
and CGS unit system of unit.
Answer:
CGS means Centimeter Gram Second while FPS means Foot Pounds Second
Explanation:
FPS is the standard used to measurement of length, mass and time. The unit of length is foot.
The time is calculated as the unit of seconds. CGS is the measurement of length, mass and time in units of centimeter, gram and second respectively
what will happen to satellite if the linear speed is reduced?. give a reason for your answer
Explanation:
If the satellite is moving too quickly then the gravitational attraction between the Earth and the satellite is too weak to keep it in orbit. If this is the case, the satellite will move off into space. This occurs at speeds around or above 11,200 metres per second (m/s).
A cyclist traveling at 30.0m/s along a straight road comes uniformly to stop in 5.00s. Determine the stopping acceleration, the stopping distance.
Answer:
I. Stopping acceleration = 6 m/s²
II. Stopping distance, S = 75 meters
Explanation:
Given the following data;
Final velocity = 30 m/s
Time = 5 seconds
To find the stopping acceleration;
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
Substituting into the equation;
[tex]a = \frac{30 - 0}{5}[/tex]
[tex]a = \frac{30}{5}[/tex]
Acceleration = 6 m/s²
II. To find the stopping distance, we would use the third equation of motion;
[tex] V^{2} = U^{2} + 2aS [/tex]
Where;
V represents the final velocity measured in meter per seconds.
U represents the initial velocity measured in meter per seconds.
a represents acceleration measured in meters per seconds square.
Substituting into the equation, we have;
30² = 0² + 2*6*S
900 = 12S
S = 900/12
S = 75 meters
ASAP
A light wave travels through glass (n=1.50) at an angle of 35°. What angle
does it have when it passes from the glass into the air (n = 1.0)?
A. 59.4
B. 0.860
C. 22.5
D. 0.382
Answer:
A. 59.4
Explanation:
The refractive index of the glass, n₁ = 1.50
The angle of incidence of the light, θ₁ = 35°
The refractive index of air, n₂ = 1.0
Snell's law states that n₁·sin(θ₁) = n₂·sin(θ₂)
Where;
θ₂ = The angle of refraction of the light, which is the angle the light will have when it passes from the glass into the air
Therefore;
θ₂ = arcsin(n₁·sin(θ₁)/n₂)
Plugging in the values of n₁, n₂ and θ₁ gives;
θ₂ = arcsin(1.50 × sin(35°)/1.0) ≈ 59.357551° ≈ 59.4°
The angle the light will have when it passes from the glass into the air, θ₂ ≈ 59.4°.
Answer:
A. 59.4
Explanation:
got it right, trust
A 0.1 kg popper is placed on a table. When it pops
up, it reaches a height of 2.0 meters. What was the
initial velocity of the popper off the table?
Answer:
The initial velocity of the pooper off the table is approximately 9.264 m/s
Explanation:
The mass of the popper, m = 0.1 kg
The height the popper reaches, h = 2.0 meters
The initial velocity of the popper, 'u', is given by the following kinematic relation;
v² = u² - 2·g·h
Where;
h = The height the popper reaches = 2.0 m
v = The final velocity of the popper at the height it reached = 0 m/s
u = The initial velocity of the pooper off the table
g = The acceleration du to gravity, g ≈ 9.81 m/s²
Plugging in the values gives;
0² = u² - 2 × 9.81 × 2.0
∴ u - √(2 × 9.81 × 2.0) ≈ 9.264
The initial velocity of the pooper off the table, u ≈ 9.264 m/s.