Achild is sliding down a slide at the playground. is the mechanical energy conserved. why or why not.
a the mechanical energy isn't conserved. some energy is lost to gravity
b the mechanical energy is conserved. there is as ke at the end as there was pe at the beginning
c. the mechanical energy isn't conserved. some energy was lost to friction
d. mechanical energy is always conserved

The correct answer is C.

Explanation:

According to the law conservation of the mechanical energy, the total mechanical energy in a closed system remains constant in the absence of friction.

In the given problem, a child is sliding down a slide at the playground.

When a child is on the top of the slide then the he has more potential energy. When he starts slides down the slide then the kinetic energy starts increasing.

At the bottom of the slide, he has more kinetic energy.

But some energy is lost here due to friction. Hence, the mechanical energy is not conserved.

Therefore, the correct option is C.

carla slowed down in the beginning of her trip, stopped, and then sped up