Physics Textbook Questions: Conservation of Energy (pg 7)

a) If the brakes are applied at the bottom of a rollercoaster's descent, the kinetic energy which has been converted from GPE will be converted to heat and sound as the tracks get friction from the wheels stopping and they squeak against the rails.

b) If the rollercoaster goes up and over another hill, its kinetic energy will convert into equal GPE by the time it has reached the top, and as it descends this will convert back into equal kinetic energy.

a) A ball dropped onto a trampoline will lose GPE and gain equal kinetic energy as it falls. When it hits the trampoline, this will be converted into sound and elastic energy as the trampoline bends downwards and pushes it back up. The energy which wasn't lost to other types will propel it back up via kinetic energy, which converts into GPE, peaking as it reaches its rebound height.

b) At the point of release, the ball has only GPE. At the top of its bouncem it has GPE but less as it isn't as high and some energy has been converted to the sound and small bit of heat energy when it hit the trampoline.

c) You would drop the ball onto each trampoline at the same time and measure the rebound height. This would be done 2/3 times with each trampoline type to get an average. The highest rebound is the bounciest the trampoline.

As the capsule moves upwards, the elastic energy increases as the rubber bands stretch. This is converted into kinetic energy, which is converted into more GPE the higher you travel. At the top, you have the least kinetic energy, but the most elastic and GPE.