Which of the following must be true about an object for it to be in uniform circular motion? a. it must have zero centripetal acceleration. b, it must have increasing centripetal acceleration. c. it must be moving at a constant speed. d. it must be moving with a constant velocity.

It must be moving at a constant speed

Explanation:

When an object move in a circular path, its motion is called uniform circular motion. The object moves with constant speed but the direction always changes. We know that the rate of change of velocity is called acceleration of the object.

In circular motion, the centripetal acceleration act towards the center of circle. The force acting on the object is called centripetal force. It is given by :

Hence, the statement that is true about an object to be in uniform circular motion is (C) " It must be moving at a constant speed".

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j