does an object speed up or slow down when:

Question

1. its velocity is positive (right) and its acceleration is positive (right)? I said it speeds up
2. its velocity is positive (right) and its acceleration is negative (left)? I said it slows down
3. its velocity is negative (left) and its acceleration is negative (left)? I said it slows down

what is the rational for this to happen and am I correct with my answers?

Answer 1

if the acceleration is in the same direction as the velocity, the object speeds up.

Otherwise, the acceleration opposes the velocity, so it slows down.