Question

True or False: A cyclist coasts down one hill and up another hill until she comes to a stop. The point at which the bicycle stops is lower than the point at which it started coasting because part of the original potential energy has been converted to a quantity of heat and this makes the tires of the bicycle warm.

Answer 1

End point is below the starting point so there is loss in potential energy .

Cyclist also has done some work by pushing the peddles.

Intially work done+ loss in potential energy was converted into kinetic energy of cycle but to stop the cycle she has to apply brakes and friction will do negative work .

As a result kinetic energy will convert into heat and tyres will get warm.

So above statement is TRUE