Energy

When is E_g the greatest in a roller coaster?

• a. at the bottom of the first hill

• b. at the top of the first hill

• c. at the top of the second hill

• d. at the bottom of the second hill

After an energy conversion, you end up with the same total amount of energy as the original amount of energy. Which of the following laws explains this rule?

• a. law of energy changes

• b. law of conservation of energy

• c. law of power and energy

• d. law of potential energy

What type of energy is in this picture?

• Kinetic

• Elastic

• Chemical

• Gravitational

Rank the points from lowest to highest E_k.

• Z, X, Y, W

• W, Y, Z, X

• Z, Y, X, W

• W, X, Y, Z

How much potential energy would the roller coaster car have at point W if the height was 20 m and the mass of the car was 10 kg?

• 200 J

• 1000 J

• 2000 J

• 2,000,000 J

A ball with a mass of 1 kg is moving with a velocity of 10 m/s. How much kinetic energy does it have?

• 2.5 J

• 5 J

• 10 J

• 20 J

A spring with a spring constant, k, of 3 N/m is stretched by 2 m. How much Elastic energy is stored in the spring?

• 6 J

• 12 J

• 24 J

• 48 J

A point W, all energy is Eg. At point X, all energy is Ek. That means that mgh = 1/2mv². Looking at this equation, does the mass of the car or number of riders make any difference in the speed of the car at point X.

• Yes

• No

The unit used to measure work is the 

• Watt

• Newton

• Joule

• meter

A 50 kg block is lifted 10 m by a crane. How much work was done?

• 50000 J

• 5000 J

• 500 J

• 50 J