Work & Energy Physics eschool

Calculate the Kinetic Energy (KE) of a girl whose mass is 50 kg who is moving at 4 m/s.

• 200 J
• 800 J
• 400 J
• 100 J

A 10.0 kg box is accelerated from 2.0 m/s to 4.0 m/s.  What is the amount of work in joules needed to accelerate the box?

• 50.0
• 60.0
• 20.0
• 45.0

True or false: when the distance an object moves is zero the work done on the object is also zero.  

• True
• False

Belly-Flop Bernie dives from atop a tall flagpole into a swimming pool below. His potential energy at the top is 10,000J. What is his kinetic energy when his potential energy reduces to 9.7J?

• 9.81J
• 10,000J
• 9.7J
• 9,990.3J

What is the work done when a 20-N force pushes a cart 3.5 m?

• 70J
• 6.8J
• 23.5J
• 17.5J

The work-kinetic energy theorem says that the net work done by all the forces acting on an object is equal to the change in the object's _____.

• mechanical energy
• work
• momentum
• kinetic energy

As a pendulum swings from its highest to lowest position, what happens to its kinetic and potential energy? 

• Both the potential energy and kinetic energy decrease
• The potential energy decreases while the kinetic energy increases 
• The kinetic energy decreases while the potential energy increases 
• Bothe the potential energy and kinetic energy increase 

While a boulder is on the top of a hill it has what type of energy? 

• Mechanical
• Kinetic
• Potential 
• Reactive 

Where is the car moving fastest?

• A

• B

• C

• D

Where does the car have the most gravitational PE?

• A

• B

• C

• D