Question

Which of the following remains constant while throwing a ball upward?

• A. Displacement
• B. Kinetic energy
• C. Acceleration (g)
• D. Velocity

Hint:

Only one force, gravity, acts on the ball throughout its flight. What quantity does gravity fix at every instant?

Answer 1

The Correct Option is C

Step 1: When a ball is thrown straight up, gravity is the only force acting on it, air resistance ignored.

Step 2: Gravity produces a constant downward acceleration of magnitude g, close to \(9.8\ m/s^2\), at every point of the flight, going up or coming down.

Step 3: Displacement keeps changing as the ball rises and falls. Velocity keeps decreasing on the way up, becomes zero at the top, then increases downward, so it is not constant. Kinetic energy depends on velocity, so it also changes and becomes zero at the highest point.

Only the acceleration stays the same in magnitude and direction throughout the motion. The correct answer is option C.