Question

Change in state of motion of an object can be described as:

• A. Change in speed only
• B. Change in direction only
• C. Change in either speed or direction
• D. Change in neither speed nor direction

Answer 1

The correct option is C

Change in either speed or direction

Explanation for correct option:

In the case of option C,

1. The phenomenon in which the position of an object changes with respect to space and time is known as motion. And when the position of a body does not change with space and time it is said to be in a state of rest.
2. According to Newton's first law of motion, “A body continues to be at rest or move in a direction with a uniform velocity until an external force is applied on it.”
3. So, if a force is applied to a body its velocity changes. And thus, the state of motion of a body changes when its velocity changes.
4. Velocity can be defined as the speed of a body in a given direction. Thus, when velocity changes both speed and direction of a body can change. Even if either one of them changes, the velocity of a body changes.
5. Thus, a change in the state of motion can be described as a change in either speed or direction.

Hence, option C is correct.