What will you need to measure in order to investigate whether a collision between two carts conserves momentum and energy? Assume the collision is taking place on a level surface, and the wheels of the carts roll freely (no friction losses).

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.