Energy Calculations

What kind of energy does a marble at the top of a hill have?

• gravitational potential

• chemical potential

• kinetic

• thermal

If the marble had a mass of 0.3kg and the hill was 2.3 m tall, how much potential energy did it have at the top of the ramp?

• 2.3 J

• 0.23 J

• 6.9 J

• 5.2 J

What is the correct unit for energy?

• meters (m)

• kilogram meters per second (kg m/s)

• Newtons (N)

• Joules (J)

If the 0.3 kg marble was moving at 6 m/s at the bottom of the ramp, how much kinetic energy did the marble have?

• 5.4 J

• 1.8 J

• 3 J

• 6 J

What does conservation of energy mean?

• Total energy increases

• Total energy decreases

• Total energy in the universe stays the same

If the marble had 6.9 J of (potential) energy at the top of the hill and 5.4 J of (kinetic) energy at the bottom of the hill, was energy conserved and why?

• No because total energy in the universe decreased

• Yes because the total energy in the universe changed

• Yes because the total energy in the system stayed the same

• Yes, but energy left the system

If the marble hits a basketball which makes the tennis ball roll across the lab table, what kind of energy transfer happened?

• kinetic-potential

• kinetic-kinetic

• kinetic-electrical

• kinetic-thermal

If the 1.2 kg basketball rolls at 3 m/s, what is it's kinetic energy?

• 2.7

• 5.4

• 3.6

• 9

The marble had 5.4 J of kinetic energy and then hit the stationary basketball. The basketball started rolling and the marble stopped rolling. The rolling basketball now has 5.4 J of kinetic energy. Was energy conserved and why?

• Yes because the total energy stayed the same

• Yes because the total energy changed

• No because the total energy stayed the same

• No because the total energy changed

It takes 20 N of force to move a box a distance of 10 m. How much work is done on the box in Joules?

• 200 J

• 20.0 J

• 100 J

• 10 J