A piece of chalk is thrown vertically upward and caught during its descent at the same height from which it was thrown. The position of the chalk is measured from when it left the hand. The positive direction for position, velocity, and acceleration is upward.
What are the signs of the position, velocity, and acceleration during the ascending part of the trajectory?
Select an Answer
The correct answer is positive position, positive velocity, and negative acceleration. As the chalk ascends, its position is above the point of release at the hand so it is positive. The chalk is moving upward so its velocity is positive. The gravitational force is downward, so the acceleration of the chalk is also downward and therefore negative.