Work and Energy Summative 2022-23

How much force is required to stretch a spring by 10 cm if its spring constant is 5 N/cm?

• 50 N

• 0.5 N

• 2.0 N

• 0 N

A 15 N weight is hung on a spring, and the spring stretches vertically by 3.0 cm. What is the direction and magnitude of the spring force?

• 15 N, upward

• 5 N, down

• 15 N, down

• 5 N, upward

Different springs were compared in terms of how much they stretched when various weights were placed on them. How do the springs compare based on the results shown in the graph? (Choose TWO answers).

• Spring A is the stiffest spring

• Spring D has the smallest spring constant

• Spring D is the stiffest spring

• Spring A has the smallest spring constant

What is the kinetic energy of a 0.20 kg baseball traveling at 45 m/s?

• 200 J

• 400 J

• 5 J

• 1000 J

A 50 kg bowling ball is hanging out a window that is 30 meters above the ground. How much potential energy does it have?

• 15000 J

• 0 J

• 1500 J

• 45000 J

A 1500 kg car is moving at 20 m/s when the brakes are applied. The brakes apply a constant force of 800 N over a distance of 10 meters. How much work is done by the brakes?

• 8000 J

• 1600 J

• 15000 J

• 30000 J

A 50 kg bowling ball is hanging out a window that is 30 meters above the ground. What will its maximum speed be just before hitting the ground?

• 25 m/s

• 60 m/s

• 10 m/s

• 5 m/s

A 0.20 kg baseball is traveling at 45 m/s when it hits a spring with a spring constant of 25 N/m. How much will the spring compress until the ball comes to rest?

• 4 m

• 16 m

• 1 m

• 8 m

A 10 kg ball and a 5 kg ball are both sent down a ramp that is 2.0 meters tall. Which of the following statements is FALSE?

• The 10 kg ball will have greater kinetic energy at the bottom

• The 10 kg ball will have a greater speed at the bottom

• Both objects will have zero potential energy at the bottom of the ramp

• The 10 kg ball will have twice as much potential energy at the top of the ramp

During which of the following situations would a system have a change in total mechanical energy?

• An object speeds up as it slides down a ramp

• A spring launches an object up into the air

• Air resistance causes an object to slow down as it falls

• A running man grabs a rope and swings up into the air