Question

The term state of motion applies to:
A) only a moving body
B) only a body at rest
C) a body moving and at rest as well
D) neither a moving body nor to one at rest

Answer 1

Use the concept of velocity in cases like a moving body and a body a rest.

Complete step by step solution:
We know that the state of motion is the condition of the motion of a body and it is defined by its velocity. If the velocity of a body is zero, then the body is not moving, that is the body is at rest whereas the body has some velocity, then it is moving with a certain speed in a direction.
Let us understand with the help of an example, when you project a stone in the air, it has some velocity, but when it lands on the surface, it comes to rest because it has zero velocity.

Hence, the state of motion applied to a body moving and at rest as well and option (C) is correct.

Additional information :According to Newton's first law, an object will remain in the state of rest or uniform motion unless external force is acted upon the object. This shows that the body will not change its state of motion itself. This tendency of a body to remain at rest or in a uniform motion is termed as inertia of a body. Therefore, Newton’s first law is also known as law of inertia.

Note: Velocity is the change in the position of the body per unit time. If the position of the body does not change, then the body is at rest and if the position changes, then the body is not at rest.