Describe a situation in which kinetic energy is transformed into thermal energy

You're driving along, and you see the light turn red, 1/2 block
in front of you.  You gently put on the brakes.

The car loses kinetic energy and slows down.

The brakes absorb the kinetic energy, and they heat up.


If you're, let's say, coming down a mountain or a really long
hill, then the potential energy you had at the top changes to
kinetic energy, little by little, as you come down.  Whenever
the speed of the car gets too high, you push the brakes to
slow it down.  Then you take your foot off of the brakes, and
let them cool.

If you don't do that, and instead you keep your foot on the brakes
all the time, then the brakes keep getting hotter and hotter, and
by the time you get to the bottom, you have flames shooting out
from the hubcaps and burning the paint off the fenders !
I only saw this happen once, many years ago, when I was in a car
coming down a long road from the top of a mountain in China.
Thank goodness I was not the person who was driving !
I would have been seriously embarrassed.

Fitness is the ability to perform only very light levels of physical activity.