A ball is released at the point x=2m on an inclined plane with a nonzero initial velocity. After being released, the ball moves with constant acceleration. The acceleration and initial velocity of the ball are described by one of the following four cases: case 1, a>0,v0>0; case 2, a>0,v0<0; case 3, a<0,v0>0; case 4, a<0,v0<0.

heeellpppp

## Answers (1)

Case one. If it has a constant acceleration, a has to be greater than 0 (a>0), otherwise, if a were negative, it would be decelerating, or slowing down. V-not (Vo = initial velocity) can be greater than 0 if you decide that down is the positive vector direction. If you decide down to be the negative vector direction, then it would be case two, because acceleration is the acceleration due to gravity (it is moving only because of the force of gravity) which is positive, and then negative would be less than 0 (when referring to Vo).

Simply put, it depends which direction you choose as negative or positive when talking about velocity. Since it starts out going down, I would personally choose down as being negative, but either CASE 1 or CASE 2 are acceptable as long as you elaborate.

Reference:I'm a physics major.