Energy conversions and conservation

Which of the following best represents the Law of Conservation of Energy?

• Energy can be created but NOT destroyed

• Energy can be destroyed but NOT created

• Energy can NOT be created or destroyed

• Energy can be created and destroyed

Which of the following positions has the greatest amount of gravitational potential energy?

• A

• B

• C

• D

If the mass of the cart is 50 kg and has a height of 40 meters, how much potential energy does it have? (PE=mgh, g=9.8m/s²)

• 1.25 Joules

• 45 Joules

• 2000 Joules

• 19,600 Joules

As soon as the roller coaster heads down the hill the potential energy converts into...

• electrical energy

• chemical energy

• Kinetic energy

• nuclear energy

If we know that Position A has 19.600 Joules of Potential energy, how much kinetic energy will there be at Position B?

• 19,600 Joules

• 9,800 Joules

• 4,900 Joules

• 0 Joules

We know kinetic energy at Position B will equal the potential energy at Position A based on....

• Newton's 2nd Law

• Newton's 3rd Law

• The Law of Conservation of Mechanical energy

• The Law of Gravity

We calculate the speed of the 50kg coaster and it clocks at 25 m/s at Position B, how much kinetic energy does it have? (KE=0.5mv²)

• 625 Joules

• 1,250 Joules

• 31,250 Joules

• 15,625 Joules

Calculations show the KE is always less than the original amount of PE. Where did the extra energy go?

• converts to electromagnetic due to friction on the tracks

• converts to mechanical energy as potential and kinetic

• converts to thermal due to friction on the tracks

• It goes into space

Choose the correct energy conversion

• electrical to thermal

• thermal to electromagnetic

• electrical to chemical

• chemical to mechanical

Choose the correct energy conversion

• thermal to nuclear

• chemical to mechanical

• electric to chemical

• mechanical to electromagnetic