Chapter 3, Problem 1RCQ

What is Newton’s first law of motion?

To determine

To know:

Newton’s first law of motion.

Answer to Problem 1RCQ

Solution:

Every object continues to be in its state of rest or its state of motion with uniform speed in the same direction (or in a straight line), unless it is acted upon by a nonzero or unbalanced force.

Explanation of Solution

We know that inertia is an inherent property of any object due to which it has tendency to resist any change in its state of motion. For ex: a book kept on table is in state of rest. In other words, it is stationary or it has zero speed. It will neither change its position nor its speed, i.e. it will not move, unless someone applies a force on it.

On the other hand, if an object is moving with a uniform speed in a certain direction, then it will continue to move without changing either its speed or its direction, unless some force acts on it. For ex: an object moving with speed $10 m/s$ towards North will keep on moving with same speed, in the same direction, unless a force is applied on it which might change its speed, direction or both.

Since Newton’s first law of motion is directly related to inertia of the object, therefore, this law is also called as Law of Inertia.