Work
Define "work" in physics.
Work is done when a force moves an object in the direction of the force.
What is the formula for potential energy?
PE= mgh
What is the formula for kinetic energy?
KE =1/2mv^2
What is the formula for power?
P=W/t
If a force is applied but the object doesn’t move, how much work is done?
0 J
A force of 10.0 N moves an object 5.00 meters. How much work is done?
W=F⋅d=10⋅5=50.0 J
What is the gravitational constant (g) on Earth?
9.81 m/s2
A 3.0 kg ball is moving at 4.0 m/s. What is its kinetic energy?
24J
Define power in physics.
Power is the rate at which work is done.
What is the total mechanical energy of an object?
ME = PE + KE
A box is pushed with a force of 20.0 N for 3.00 meters. How much work is done?
W = 60.0 J
A 2.0 kg book is placed 5.0 meters high on a shelf. What is its potential energy?
98J
If the velocity of an object doubles, what happens to its kinetic energy?
KE increases by 4 times because velocity is squared.
A student does 100 J of work in 5 seconds. What is the power output?
20W
A 10 kg object is lifted to a height of 2 meters and released. What is its KE just before it hits the ground?
KE = PE at the top =196J
A person lifts a 15.0 kg box 2.00 meters high. How much work is done?
294 J
A diver (50.00 kg) is standing on a diving board 10.00 meters above the water. Find their potential energy.
4900. J
A car with a mass of 1,000 kg is moving at 10 m/s. Calculate its kinetic energy.
50,000J
A motor lifts a 200 N object 10 meters in 4 seconds. What is the power?
500W
A 5 kg object has a velocity of 6 m/s. What is its KE, and how much power is required to produce this KE in 3 seconds?
KE = 90 J
P= 30 W
A car engine exerts a force of 500 N over 100 meters. How much work is done?
50,000J
A rock has 500.0 J of potential energy. If its mass is 10.00 kg, how high is it above the ground?
5.100 m
A ball has a kinetic energy of 80 J and a mass of 2 kg. What is its velocity?
8m/s
A car engine generates 3000 W of power for 10 seconds. How much work is done?
30,000J
An object has 200 J of PE and 50 J of KE. What is its total mechanical energy?
250 J