Physics - Work, Kinetic, and Potential Energy

A car traveling at 60 mph has how much more energy than a car going at 20 mph?

K.E. increases by a factor of _____ times.

9

How much farther will a car skid if it locks its brakes at 60 mph as compared to a skid from 15 mph? Assume the braking force that will eventually stop the cars is provided by the road and that it acts with equal magnitude in both situations.

Distance increases by a factor of __________ times.

16

A 1451 kg car is traveling at 48.0 km/h.

How much kinetic energy does it possess? K.E. =

1.28 x 10^5 J

A 1451 kg car is traveling at 48.0 km/h.

Compared to 48.0 km/h, what would be the fraction of energy the car would have if it were traveling at 24.0 km/h.

K.E. =

one fourth

A force of 80 N is exerted on an object on a frictionless surface for a distance of 4 meters. If the object has a mass of 10 kg, calculate its velocity.

v = _____ m/s

8

How many times does the kinetic energy of a car increase when traveling 60 mph as opposed to traveling 30 mph?

K.E. increases

four

A rock with mass of 5.0 kg is carried up a small hill 1 0 meters high. What is the potential energy of the rock at the hilltop?

P.E. =

490

A rock with mass of 5.0 kg is carried up a small hill 1 0 meters high. How much work had to be done in carrying the rock up hill?

W =

490 J

A 2 0 -kg barrel is rolled up a 2 0 -m ramp to the back of a truck whose floor is 5.0 m above the ground. What work is done in loading one barrel into the truck?

980 J

How much potential energy does a 2 0 -kg barrel have when it is in the truck whose floor is 5.0 m above the ground?

P.E. =

980 J

Match the following examples of energy with the primary form of energy exhibited.

1. friction

2. nuclear power plant

3. toaster element

4. welding torch

5. eraser sitting on a desk edge

6. light bulb

7. campfire

8. moving car

9. lump of coal in a storage bin

10. stick of tnt

1. heat

2. nuclear

3. heat

4. heat

5. potential

6. light

7. heat

8. kinetic

9. potential

10. potential

Not all energy sources derive their energy from the sun. Choose the three from the list below that derive their energy from sources other than the sun.

chemical, geothermal, nuclear

The total energy of the universe remains constant.

True