Answer:
-50.6 kJ
Explanation:
The work done (W) on an object is given by:
W = (Fcosθ) * S
where F is the force, S is the displacement and θ is the angle between the force and displacement.
i) During the first trip riding east, S₁ = 2.93 km = 2930 m, F₁ = 8.65 N.
The displacement is due east and the force is due west, hence θ₁ = 180°. Therefore:
W₁ = (F₁ * cosθ₁)S₁ = (8,65 * cos(180))2930 = -25.3 kJ
ii) i) During the second trip riding west, S₂ = 2.93 km = 2930 m, F₂ = 8.65 N.
The displacement is due west and the force is due east, hence θ₂ = 180°. Therefore:
W₂ = (F₂ * cosθ₂)S₂ = (8,65 * cos(180))2930 = -25.3 kJ
work done by the resistive force during the round trip is:
W = W₁ + W₂ = -25.3 kJ + (-25.3 kJ) = -50.6 kJ
Please answer this question sqdancefan
Answer:
(D) 4
Explanation:
The percentage error in each of the contributors to the calculation is 1%. The maximum error in the calculation is approximately the sum of the errors of each contributor, multiplied by the number of times it is a factor in the calculation.
density = mass/volume
density = mass/(π(radius^2)(length))
So, mass and length are each a factor once, and radius is a factor twice. Then the total percentage error is approximately 1% +1% +2×1% = 4%.
_____
If you look at the maximum and minimum density, you find they are ...
{0.0611718, 0.0662668} g/(mm²·cm)
The ratio of the maximum value to the mean of these values is about 1.03998. So, the maximum is 3.998% higher than the "nominal" density.
The error is about 4%.
_____
Additional comment
If you work through the details of the math, you will see that the above-described sum of error percentages is just an approximation. If you need a more exact error estimate, it is best to work with the ranges of the numbers involved, and/or their distributions.
Using numbers with uniformly distributed errors will give different results than with normally distributed errors. When such distributions are involved, you need to carefully define what you mean by a maximum error. (By definition, normal distributions extend to infinity in both directions.) While the central limit theorem tends to apply, the actual shape of the error distribution may not be precisely normal.
Answer:
D. 4Explanation:
#CARRYONLEARNING
justoko2
with respect to air the refractive index of ice is 1.31 and that of rock salt is 1.54 calculate the refractive index of rock salt with respect to ice
Answer:
1.17
Explanation:
Given that,
The refractive index of ice wrt air = 1.31
The refractive index of rock salt wrt air = 1.54
We need to find the refractive index of rock salt with respect to ice.
We know that,
refractive index = (speed of light in air or vaccum)/( speed of light in that medium)
So,
The speed of light in ice = c/(1.31)
The speed of light in rock salt = c/(1.54)
So, the refractive index of rock salt with respect to ice is :
[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]
So, the required refractive index of rock salt wrt ice is 1.17.
A particular solid is an excellent conductor of thermal energy. Is it more likely to be a metal or a non-metal?
Match the reactants with the products. zinc sulfate + copper aluminum chloride + copper copper oxide copper + water copper sulfate + oxygen
Answer:
The Reactants Products
Copper sulfate + zinc → Zinc sulfate + copper
aluminum + copper chloride → Aluminum chloride + Copper
Copper + Oxygen → Copper oxide
Explanation:
The Reactants Products
Copper sulfate + zinc Zinc sulfate + copper
aluminum + copper chloride Aluminum chloride + Copper
Copper + Oxygen Copper oxide
First reaction can be described as a single replacement reaction
Second reaction is also a single replacement reaction just like the first reaction
The third is a synthesis reaction ( i.e. reaction in which elements combine to form single compound )
Eratosthenes measured the circumference of Earth to within 4% of the correct value
A. Looking at stick shadows on the equinox.
B. Noting how much more of the celestial sphere came into view when walking south.
C. Sighting the stars from within the deepest well in Egypt on the day of the solstice.
D. Using the detailed reports of far-sailing mariners
Answer:
A. Looking at stick shadows on the equinox.
Explanation:
He measures the circumference by placing a pole when the sun is overhead on the days of solstice. He determined the circumference by measuring the difference between Alexandria to Syene and the angle of the pole's shadow.
The equation used for the calculation of circumference is as follow
[tex]\frac{360 degrew}{7.2 degree} = \frac{Circumference of earth}{Distance from Alexandria to Syene}[/tex]
Please refer to the following link for more details
https://www.khanacademy.org/humanities/big-history-project/solar-system-and-earth/knowing-solar-system-earth/a/eratosthenes-of-cyrene
Which has greater kinetic energy, a car traveling at 40 mph or a half-as-massive car traveling at 80 mph?
a
-The 40 mph car
-The 80 mph car
-Both have the same kinetic energy
-Neither has kinetic energy
Answer:
The 80 mph car
Because the formula says 1/2 mass but for the velocity it is squared
Two uniform bars of the same dimensions are constructed from the same material. One bar has five evenly spaced holes through it and the second bar has only two holes. In these cases, the bars are slid over vertical pegs and rest on a horizontal surface, where friction between the bar and the surface is negligible. The two bars are each pulled by
horizontal forces of equal magnitude F from their right end as shown above. The bars' resulting angular accelerations are recorded.
Is the magnitude of the initial angular acceleration of the bar in case 1 larger than, smaller than or equal to the magnitude of the initial angular acceleration of the bar in Case 2? Explain your reasoning.
Solution :
The angular acceleration, [tex]$\alpha$[/tex] is obtained from the equation of the [tex]$\text{Newton's second law}$[/tex] of rotational motion,
Thus,
[tex]$\tau = F \times d$[/tex]
or [tex]$\tau = I \times \alpha$[/tex]
where [tex]$\tau$[/tex] is torque, F is force, d is moment arm distance, I is the moment of inertia
Thus, [tex]$\alpha=\frac{(F\times d)}{I}$[/tex]
Now if the force and the moment arm distance are constant, then the [tex]\text{angular acceleration is inversely proportional to the moment of inertia.}[/tex]
That is when, F = d = constant, then [tex]$\alpha \propto \frac{1}{I}$[/tex] .
Thus, moment of inertia, I is proportional to mass of the bar.
The mass is less for the bar in case (1) in comparison with that with the bar in case (2) due to the holes that is made in the bar.
Therefore, the bar in case (1), has less moment of inertia and a greater angular acceleration.
A room has a rectangular shape of 4000 mom by 3600mm according to the architecture plan It is supposed to be fitted with tiles which are square in shape and size of 12 cm. How many tiles are required to cover the entire floor
Explanation:
First find the area of the entire floor:
Area of a rectangle= length × width
( 4000mm× 3600mm)
14400000mm²
Area of one square tile??= side ×side
12cm×12cm
144cm²
Convert cm to mm
1cm²=100mm²
144cm²=144cm²/1cm²×100mm²
=14,400mm²
Number of tiles required to cover the entire floor= 14400000mm²/14400mm²
=1000
Explain hydraulic machine as force multiplier.
Answer:
The pressure on piston 1 is always equal to the pressure on piston 2. ... It is equal to the force on piston 1, multiplied by A2/A1. Hydraulic systems are called force multipliers for exactly this reason. A small force can be increased by using hydraulics
Explanation:
Radhe Radhe❤
In an experiment Rahul burnt 4 kg fuel and the heat produced was measured to be 160,000 kJ and Raj burnt 2 kg of fuel and heat produced was measured to be 100,000kJ. Calculate the net calorific value of the fuels.
Answer:
The net calorific value of the fuel 1 is 40000 kilojoules per kilogram.
The net calorific value of the fuel 2 is 50000 kilojoules per kilogram.
Explanation:
The net calorific value is equal to the heat produced ([tex]Q[/tex]), in kilojoules, divided by the mass of the burnt fuel ([tex]m[/tex]). We proceed to calculate the net calorific value of each fuel:
Fuel 1 ([tex]m = 4\,kg[/tex], [tex]Q = 160000\,kJ[/tex])
[tex]L = \frac{160000\,kJ}{4\,kg}[/tex]
[tex]L = 40000\,\frac{kJ}{kg}[/tex]
The net calorific value of the fuel 1 is 40000 kilojoules per kilogram.
Fuel 2 ([tex]m = 2\,kg[/tex], [tex]Q = 100000\,kJ[/tex])
[tex]L = \frac{100000\,kJ}{2\,kg}[/tex]
[tex]L = 50000\,\frac{kJ}{kg}[/tex]
The net calorific value of the fuel 2 is 50000 kilojoules per kilogram.
what is the formula to calculate liquid pressure?/
1. set up the equation
2. multiply the variables
3. analyze your results
A football is projected at an angle of 30 from the ground with a n initial velocity of 10 m/s, take acceleration due to gravity is g= 10m/s2 .what is the time of flight
Answer: i dont know
Explanation:
Answer:
[tex]{ \bf \: time \: of \: flight : s = 0} \\ { \tt \: s \: is \: displacement} \\ \\ s = ut + \frac{1}{2} a {t}^{2} \\ 0 = u \sin( \theta) t - \frac{1}{2} g {t}^{2} \\ u \sin( \theta)t = \frac{1}{2} g {t}^{2} \\2 u \sin( \theta) = gt \\ { \boxed{ \tt{formular : time \: of \: flight = \frac{2u \sin( \theta) }{g} }}} \\ t = \frac{2 \times 10 \times \sin(30 \degree) }{10} \\ { \green{ \boxed{ \tt{ \bf{answer : { \tt{time \: of \: flight =1 \: second }}}}}}} \\ \\ { \tt{becker \: jnr}}[/tex]
Ball X has a mass of 8kg and is moving toward ball Y (which is sitting still) at 2m/s. After they collide, ball X is
sitting still. How fast is ball Y moving after the collision if it has a mass of 4kg?
Answer:
v = 4 m/s
Explanation:
Given :
Ball X :
Mass, m1 = 8kg ;
Initial Velocity, u1 = 2 m/s
Final velocity, v1 = 0
Ball Y:
Mass, m2 = 4kg ;
Initial Velocity, u2 = 0 m/s
Final velocity, v2 = v
(m1u1 + m2u2) = (m2v2 + m1v1)
(8*2 + 4*0) = (4*v + 4*0)
16 + 0 = 4v + 0
16 = 4v
v = 16 / 4
v = 4 m/s
Answer:
Explanation:
This is the Law of Momentum Conservation which for us looks like this:
[tex][m_xv_x+m_yv_y]_b=[m_xv_x+m_yv_y]_a[/tex] and that should look familiar to you if this is what you are doing in physics. Filling in our particular info:
[(8.0 × 2.0)+ (4.0 × 0.0)] = [(8.0 × 0.0) + (4.0v)] and
16 + 0 = 0 + 4.0v and
16 = 4.0v so
v = 4.0 in the direction of ball X
What are various systems of unit?
Answer:
hlw its jess bregoli
your answer is here
SI (International System of Units) (meter-kilogram-second-ampere-kelvin-mole-candela)
FPS (foot-pound-second)
MKS (meter-kilogram-second)
CGS (centimeter-gram-second)
EMU (Electromagnetic) (centimeter-gram-second-abampere)
ESU (Electrostatic) (centimeter-gram-second-abcoulomb)
Atomic (bohr-electron mass-atomic second-electron)
MTS (meter-tonne-second)
Explanation:
hope it may help you !!
Answer:
there are 4 types of systems. They are ,
SI - accepted world wide
MKS - meter kilogram second
CGS - centimeter gram second
FPS - foot pound second
hope it helps.
Spending more time with her grandchildren is most likely a short-term goal
for a person of which of these ages?
A. 20 years old
B. 10 years old
C. 30 years old
D. 60 years old
Answer:60
Explanation:
gia tốc a và vận tốc v cùng chiều khi nào trong một chu kì dao động điều hòa ?
Explanation:
Khi một hạt thực hiện SHM Đang chuyển động từ vị trí cực biên về vị trí trung bình, thì vận tốc và gia tốc cùng hướng, tức là hướng về vị trí trung bình
if escape velocity and orbital velocity of a satellite for Orbit close to the Earth's surface then these are related by
Answer:
The ratio of the escape velocity to the orbital velocity is [tex]\sqrt 2[/tex].
Explanation:
The minimum velocity given to an object so that it escapes from the earth's gravitational pull is called escape velocity.
The formula of the escape velocity is
[tex]v=\sqrt\frac{2GM}{R}[/tex]
The velocity of an object in the orbit around the earth is called orbital velocity.
The formula of the orbital velocity is
[tex]v=\sqrt\frac{GM}{R}[/tex]
The ratio of the escape velocity to the orbital velocity is
[tex]\frac{v_e}{v_o}=\sqrt 2[/tex]
A pole-vaulter first converts kinetic energy into
a. thermal energy.
b. chemical energy. mechanical energy.
c. mechanical energy
d. elastic potential energy.
Answer:
d. elastic potential energy
A radio has a 1.3 A current. If it has a resistance of 35 Ω, what is the potential difference?
Answer:
22
Explanation:
Answer:
45.5 v
Explanation:
I = 1.3 A
R = 35 Ω
V = I * R
V = 1.3 * 35 = 45.5 v
A ball is dropped from the top of a building. It initially
moves at 40 m/s. After 0.5 seconds, it moves at 3.8
m/s.
What force is responsible for the slowing of the ball?
air resistance
gravity
normal
tension
Answer:
Explanation:
I'm assuming you missed the decimal point in the initial velocity and that it should be 4.0 m/s. If after a half of a second it is moving a tiny bit slower, it would be because of air resistance. You can only neglect air resistance if the problems you are doing tell you neglect it.
Answer:
Air resistance
Explanation:
I got it correct on the quiz :)
What is measurement ?
Answer:
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events
Answer:
The comparison of an unknown quantity with a known quantity is called measurement
quicklime which is calcium oxide, is made by heathig limestone in a furnace as per the equation :
CaCO3(s)CaO(s)+CO2
7.00Kg of calcium oxide was formed. what mass of calcium carbonate was heated?
Answer:
h2 PRD algo trata gevbjjgcvnkoytewxc.
Answer:
12.5kg
Explanation:
The process is explained in the paper
PLEASEE HELPP!!!
Describe melting.
Describe evaporation.
Describe boiling.
Describe condensation.
Describe freezing.
Melting: the substance changes back from the solid to the liquid
Evaporation: the process by which water changed from a liquid to a gas.
Boiling: the process by which a liquid turns into a vapor when it is heated to it's boiling point.
Condensation: the substance changed from a gas to a liquid
Freezing: the substance changed from a liquid to solid.
Answer:
Melting is a process that causes a substance to change from a solid to a liquid.
Evaporation is the process of turning from liquid into vapour.
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the
Condensation is the process of water vapor turning back into liquid water
Freezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point
Questlon 20 of 20 Which change to an object would quadruple its kinetic energy?
A. Reducing its mass to one-half of its original value
B. Increasing its velocitato twice its original value
C. Reducing its velocity to one-half of its original value O
D. Increasing its mass to twice its original value
Answer:Whenever the velocity of the object increases or usually doubles, the kinetic energy will be quadrupled. If in case you are not familiar with kinetic energy, this is known as the type of energy that is in motion. The greater the mass of the object, the greater the total of the energy
Explanation:
Change to an object would quadruple its kinetic energy Increasing its velocity to twice its original value
What is kinetic energy?
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, kinetic energy is any term in a system's Lagrangian which includes a derivative concerning time.
In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is [tex]{\textstyle {\frac {1}{2}}mv^{2}}[/tex]
In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.
The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound.
Learn more about kinetic energy
https://brainly.com/question/12337396
#SPJ2
A 4.88 x 10-6 C charge moves 265 m/s
parallel (at 0°) to a magnetic field of
0.0579 T. What is the magnetic force
on the charge?
Answer:
[tex]F=0N[/tex]
Explanation:
From the question we are told that:
Charge [tex]Q=4.88 x 10-6 C[/tex]
Velocity [tex]v= 265m/s[/tex]
Angle [tex]\theta =0 \textdegree[/tex]
Magnetic field [tex]B=0.0579T[/tex]
Generally the equation for Force is mathematically given by
[tex]F=Q(\=v*\=B)[/tex]
[tex]F=qvBsin\theta[/tex]
Therefore
[tex]F=qvBsin0 \textdegree[/tex]
[tex]F=0N[/tex]
Answer:
0 newtons
Explanation:
When a moving charge is parallel to the magnetic field, it feels no Magnetic force at all.
Even if the Magnetic Field is 100,000,000 Tesla!
Select the correct answer.
Which quantity is a vector quantity?
ОА. .
acceleration
OB.
mass
OC.
speed
O D.
volume
Reset
Next
Answer:
acceleration is the vector quantity because it depends on particular direction and has magnitude
(x – 2)² = 5(y + 1), where x and y are measured in centimeters. You need to place a new light bulb in your flashlight. How far away from the vertex of the parabolic mirror should you place the bulb to ensure a perfect beam of light? The bulb should be placed .
Answer:
The coordinates of the point the bulb should be placed is (2, 0.25)
Explanation:
The given equation of a parabola is presented as follows;
(x - 2)² = 5·(y + 1)
The point the bulb should be placed is the focus of the parabolic mirror to ensure a perfect (straight) beam
The general form of the equation of a parabola is (x - h)² = 4·p·(y - k)
The coordinates of the focus of the parabola for p > 0 f = (h, k + p)
By comparison, h = 2, k = -1, and p = 5/4
∴ The coordinates of the focus of the parabola, f = (2, -1 + 5/4) = (2, 0.25)
The coordinates of the point the bulb should be placed is at the focus, f = (2, 0.25).
A small block is attached to a spring with a spring constant of 85 N/m. When the spring is compressed 0.30 meters and the released, the 0.50 kg block is launched. What is the final speed of the block?
A)
8.42 m/s
B)
3.91 m/s
C)
7.14 m/s
D)
15.3 m/s
Answer:
Explanation:
These Hooke's Law problems are tricky. Here's what we need to know that clears up the problem entirely. The final and also the max speed of the block will be reached at the point where the potential energy of the system is 0. So the equation we need, namely,
[tex]KE+PE=\frac{1}{2}kA^2[/tex] can be simplified down to
[tex]KE=\frac{1}{2}kA^2[/tex] and we solve this first for KE:
[tex]KE=\frac{1}{2}(85)(.30)^2[/tex] and, paying NO attention whatsoever to significant digits here (because if you did the answer you get is not one of the choices)
KE = 3.825 J. Now we can use that value of kinetic energy and solve for the speed we need:
[tex]KE=\frac{1}{2}mv^2[/tex] so
[tex]3.825=\frac{1}{2}(.50)v^2[/tex] so
[tex]v=\sqrt{\frac{2(3.825)}{.50} }[/tex] so
v = 3.91 m/s
If each metal is hit with light at the minimum wavelength, can I vary the intensity of the light to start emitting electrons? Yes or no? Explain
Answer:
Consequently the statement is FALSE
Explanation:
The process of emission of electrons or photoelectric effect, was explained by Einstein, assuming that light behaves as formed by how many so-called photons and each one of them collides with an electron, therefore to start an electron the incident photon energy must be greater than the work function of the material.
E =K + Ф
By mentioning the intensity we increase the number of photons but we do not increase their energy.
Consequently the statement is FALSE
7.) A neutral atom loses two electrons. Which of the following ions might result? HELP ME ASAP!!!
Answer:
A. Mg+2
Explanation:
im not sure, but since it lost two electrons which have a negative charge it gained two charge.
