Uniform circular motion statements

[flynostrich08]

Homework Statement

Which of the following is not true in relation to an object moving in uniform circular motion?
a. KE of the object is constant
b. net force is zero
c. net work is zero
d. the magnitude of acceleration is constant
e. momentum is non-constant

The Attempt at a Solution

at first i thought it was e. but then i believe momentum relies on velocity which would not make it true so i believe the best answer is b. but not a 100% sure why

 

[Agent M27]

Your choice of B is correct because if there were no forces, the object would travel in a straight line path rather than a circular one, i.e. Newtons 1st Law. The must be some net force that is directed toward the center of the circle which is either tension or some other agency keeping the particle in circular motion. Hope that helps.

Joe