Question

A sled starts at rest with 51,450 j of potential energy. after traveling part of the way down the slope, the sled has 32,781 j of potential energy. if there is no friction, what is the kinetic energy of the sled?

Answer 1

The Kinectic energy of the sled is 18669j

Explanation:

From the above question.

Because the sled starts at rest ,

The total energy of the sled = 51,450j

The potential energy ( P.E) after traveling down the slope = 32,781 j

Total energy = Potential energy + Kinectic Energy

Kinectic Energy = Total energy - Potential Energy

Kinectic energy = 51,450 j - 32,781 j

= 18669j

Therefore, the Kinectic Energy of the sled = 18669j

Answer 2

In a mechanical system, it is a law that energy should be conserved. In this case, what is the initial energy should be equal to the total energy after the motion happened. We do as follows:

PE(at rest) = KE(during motion) + PE(after motion)
51450 J = KE(during motion) + 32781 J
KE(during motion) = 18669 J