An object is thrown upward with an initial velocity of 32.1 m/s.
When the object reaches it maximum height, it is true of the
acceleration, a, and the velocity, v, that:
both its acceleration and velocity are zero
both its acceleration and velocity change sign
velocity is equal to zero, but acceleration is not
acceleration is equal to zero, but velocity is not
None of the above.
Please help. Only one answer is true. Please give reason
why.