TEST REVIEW Work Energy Power

What is the S.I unit of work?

(Hint: pick 2)

• N.m²

• (Kg.m²) / s²

• J/m

• J

In which scenario is work = 0 J ?

• Pushing a stationary wall

• Pulling a trolley car

• Pushing a book across the table

• Dropping a set of keys from a height, h.

An object weighing 20 N moves horizontally toward the right a distance of 5.0 m. What is the work done on the object by the force of gravity?

• The work done on the object by the force of gravity is 50 J.

• The work done on the object by the force of gravity is zero joules.

• The work done on the object by the force of gravity is 4.0 J.

• The work done on the object by the force of gravity is 0.25 J.

• The work done on the object by the force of gravity is 100 J.

You pick up a 3.8 kg can of paint from the ground and lift it to a height of 1.4 m. You hold the can stationary for half a minute, waiting for a friend on a ladder to take it. How much work do you do during this time (when the can of paint was stationary)?

• 52 J

• 30 J

• 0 J

• 25 J

If the net work done on an object is positive, what can you conclude about the object's motion?

• The object is speeding up.

• The object is moving with a constant velocity.

• The object is slowing down.

• The object is at rest; its position is constant.

You raise a bucket of water from the bottom of a well that is 12 m deep. The mass of the bucket and the water is 5.00 kg, and it takes 15 s to raise the bucket to the top of the well. How much power is required?

• 39 W

• 41 W

• 43 W

• 45 W

Calculate the KE of a runner that has a mass of 80 kg and is running at a velocity of 8 m/s

• 5120 J
• 320 J
• 640 J
• 2560 J

Energy due to motion is ____________ energy. 

• Potential 
• Energy
• Kinetic
• Friction

__________ is stored energy. 

• Potential
• Kinetic
• None of the above 
• All of the above 

Gravitational potential energy depends on the ________ and ________ of the object. 

• Height and mass
• Friction and movement
• Mass and Movement
• Height and Friction