Energy Changes of Cyclist: X to Y

[Cheesus128]

Sorry for brief formulation but have no time.

Cyclist travels down hill, no pedalling.
Applies breaks at X and stops at Y.

Which energy changes have taken place between X and Y?

A. Kinetic --> internal (Heat) ---> Grav potential
B. Kinetic --> Grav Potential --> Internal heat
C. Grav Potenial --> Internal (heat) ---> Kinetic.
D. Grav Potential --> Kinetic ---> Inetnal Heat

Thank you!

 

[Melgibson]

lol are you using your blackberry during a test?

 

[Cheesus128]

Hahaha no I am just doing a Paper and don't have the marking scheme.
My IGCSE is tomorrow though.
So maybe that's a good idea ;D
Anyway know the answer?

 

[Melgibson]

Ya but i don't think I am suposed to say

 

[rdl]

I would like to provide a response to the energy changes that have taken place between points X and Y for the cyclist. The correct answer would be D. Grav Potential --> Kinetic ---> Internal Heat. This is because as the cyclist travels downhill from X to Y, the potential energy due to gravity decreases and is converted into kinetic energy. At the same time, the friction between the brakes and the wheels generates heat, resulting in an increase in internal energy. Therefore, the energy changes that have occurred are a decrease in gravitational potential energy, an increase in kinetic energy, and an increase in internal energy.