A Level Physics Practice Exam

What effect does air resistance have on the motion of a thrown ball?

1. It increases the ball's range

2. It maintains constant speed

3. It causes the ball to lose height more quickly

4. It has no impact on the ball's trajectory

The correct answer is: It causes the ball to lose height more quickly

When a ball is thrown, it experiences various forces acting on it, one of which is air resistance. Air resistance, also known as drag, opposes the motion of the ball as it travels through the air. This resistance acts in the opposite direction to the ball's velocity, which affects both its vertical and horizontal motion. The correct answer highlights that air resistance causes the ball to lose height more quickly. As the ball travels upward, the air resistance works against the force of the throw and the force of gravity. This results in a decrease in the ball's upward velocity more rapidly than would occur in a vacuum. Consequently, the ball reaches its peak height sooner and then begins to descend more quickly compared to a scenario where air resistance is negligible. In contrast, air resistance does not increase the ball's range, as it would reduce the horizontal distance the ball travels before hitting the ground. It also does not maintain a constant speed; instead, the ball experiences a gradual deceleration due to the drag force. Lastly, stating that air resistance has no impact on the ball's trajectory is inaccurate, as it clearly alters how high the ball can go and how long it stays in the air before falling back down.