Work it Out
Energy Exchange
Power Moves
Conservation Corner
Spring into Action
100
A 10N for is applied to a box to move it 5 meters. How much work is done?
50J
100
A 2-kg object is lifted 3 meters above the ground. How much gravitational potential energy does it have?
58.8J
100
Write 2 possible units for power
W or J/s
100
A 1kg rock is thrown off the roof. It hits the ground at 15m/s. How high was the roof? (Use energy)
11.5m
100
A certain spring requires 15N of force to be compressed 0.5m. What is the spring constant?
30 N/m
200
A person applies a force of 20N to an object at an angle of 90 degrees. The object moves 3m. How much work is done?
0J (force is perpendicular to the motion)
200
A 0.5kg ball is dropped from a height of 4 meters. What is its kinetic energy just before it hits the ground?
19.6J
GPE --> KE
200
A machine exerts a power of 50 watts for 5 seconds. How much work does it perform?
250J
200
A roller coaster car starts from rest at the top of a 10-meter hill. If there is no friction, what is the speed of the car at the bottom of the hill?
14 m/s
200
A 3kg mass is attached to a vertical spring with a constant of 80 N/m. How much will the spring stretch?
0.3675m
300
A crane lifts a 150kg pallet 20m. How much work is done to lift the pallet?
29,400J
300
A 65kg skier makes it to the top of a 9m hill, moving at 7m/s. How fast will she be traveling when she makes it down to the bottom of the hill?
15m/s
300
A 1200 kg car accelerates from rest to 20m/s in 10 seconds. What is the average power of the engine during this time?
24,000 W
300
A 2-kg object with a speed of 6 m/s slides along a flat surface. It eventually comes to a stop after traveling a distance of 10 meters, due to friction. How much work was done by friction?
-36J
300
A spring compressed 0.1m has 20J of potential energy. What is the spring constant of the spring?
4000 N/m
400
How much work is done while moving an object from 0 to 20m 
200J
400
m1=0.8kg, m2=1kg
If the initial height of m2 is 0.6m, with what speed will it hit the ground (0m).
1.14m/s
400
**HARD**
A cyclist exerts a force of 500N while moving at a constant speed of 8m/s. What is the power output of the cyclist?
4000W
P=W/t --> P=F*d/t --> P=F*v
400
A 2kg ball is dropped from a height of 8 meters. Upon hitting the ground, 40 J of heat is released due to energy loss from the collision. How high does it bounce?
5.96m
400
A 1.5-kg mass is attached to a horizontal spring with a spring constant of k=100 N/m. The spring is initially stretched by 0.2 m and then released. Assuming no friction, how fast is the mass moving when the spring passes through its equilibrium position?
1.63 m/s