Question

When can you say that the state of motion of an object has changed?

• A. Change in its speed.
• B. Change in its direction.
• C. Change both in magnitude and direction.
• D. All of the above.

Answer 1

Answer: (A), (B), (C)

The correct options are
A

Change in its speed.

B

Change in its direction.

C

Change both in magnitude and direction.

Consider the following examples:

1. A block of ice rests on a table. A boy pushes it and it starts moving. In this case, the state of motion of ice has changed from "being at rest" to "being in motion".
2. A cricket ball is in motion till a fielder catches it. In this case, the state of motion of the ball has changed from "being in motion" to "being at rest".
3. A volleyball player smashes an already moving ball. In this case, both the direction and speed of the ball has changed. Therefore, the initial state of motion of the volleyball has changed because of both its speed and the direction in which it is finally moving have changed.

In the examples listed above, we can understand that the state of motion of an object is changed if:

a) There is a change in the speed of the object.
b) There is a change in the direction in which the object is moving.
c) There is a change in both the direction of motion and speed of the object.