A Rectangular Block Is Moving Along a Frictionless Path When

Multiple Choice

A rectangular block is moving along a frictionless path when it encounters the circular loop as shown.The block passes points 1,2,3,4,1 before returning to the horizontal track.At point 3:

A) its mechanical energy is a minimum
B) the forces on it are balanced
C) it is not accelerating
D) its speed is a minimum
E) it experiences a net upward force