Can an Object's Velocity Change Direction When Its Acceleration Is

Multiple Choice

Can an object's velocity change direction when its acceleration is constant?

A) No, this is not possible because it is always slowing up.
B) No, this is not possible because it is always speeding up.
C) Yes, this is possible, and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example.
D) Yes, this is possible, and a rock thrown straight up is an example.
E) No, this is not possible because it is always speeding up or always slowing down, but it can never turn around.