Chapter 5, Problem 7A

In the absence of air resistance, why does the horizontal component of velocity for a projectile remain constant while the vertical component changes?

To determine

To Explain: The horizontal component of velocity for a projectile remains constant while vertical component changes.

Explanation of Solution

Introduction:

According to Newton’s law, an object experience acceleration when a force acts on it in the direction of force. In the absence of a force, the object moves with constant velocity in that direction.

During the motion of a projectile, the only force acting on it is the force of gravity in vertical direction. Hence, no force acts on the projectile in horizontal direction, so it moves at constant velocity along the horizontal direction.

Conclusion:

Hence the projectile moves at constant velocity along horizontal direction because there is no force acting on it in that direction.