A box slides down a frictionless incline, and a hoop rolls down another incline.
ID: 2245594 • Letter: A
Question
A box slides down a frictionless incline, and a hoop rolls down another incline. Both inclines have the same height, and both the box and the hoop have the same mass. If both objects start from rest, upon reaching the bottom of the incline which one will have the greater kinetic energy and which one will have the greater speed?
The correct answer is: Both will have the same kinetic energy, but the box will have the greater speed.
Okay, so I understand why the box has greater speed, because unlike the hoop, the box is not giving energy to rotational kinetic energy, but I do not understand why they have the same kinetic energy. Could someone explain this answer to me? Thank you!
Explanation / Answer
The answer is both items are starting at the sameheight with the same mass therefore the potential energies will bethe same meaning the kinetic at the bottom will also be thesame The box will have more speed because some of the hoops kineticenergy will be in the form of rotational kinetic energy and rotational speed lowering its translationial speed. All of thebox's kinetic energy will be translational meaning its speed willbe faster.Related Questions
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