Question

Define one newton force.

Answer 1

Hint:The S.I unit of force is newton. Use Newton’s second law to express one newton force. Using the S.I unit of force, define one newton force.

Complete answer:
To answer this question, let’s define force. If we are pushing or pulling the body to move it from one position to another that means we are applying the force on the body. We know that the S.I unit of force is newton. We can precisely express the unit of the force as,
\[1\,{\text{N}} = 1\,{\text{kg}}\,{\text{m}}\,{{\text{s}}^{ - 2}}\]

We have Newton’s second law of motion which states that the force acting on the body of mass m is equal to the product of mass of the body and acceleration produced in the body in response to the force. Thus, we can express Newton’s second law of motion as,
\[F = ma\]
Here, $a$ is the acceleration of the body.
We know the unit of mass is kg and the unit of acceleration is \[{\text{m}}\,{{\text{s}}^{ - 2}}\]. Now, if the mass of the body is 1 kg and the acceleration produced in the body is \[{\text{1}}\,{\text{m}}\,{{\text{s}}^{ - 2}}\], the force will be,
\[F = \left( {1\,{\text{kg}}} \right)\left( {1\,{\text{m}}\,{{\text{s}}^{ - 2}}} \right)\]
\[ \Rightarrow F = {\text{1}}\,{\text{kg}}\,{\text{m}}\,{{\text{s}}^{ - 2}}\] Or,
\[F = {\text{1}}\,{\text{N}}\]

Therefore, we can define one newton force as the amount of force required to produce \[{\text{1}}\,{\text{m}}\,{{\text{s}}^{ - 2}}\] acceleration in the body of mass 1 kg.

Note:To answer these types of questions, the key is to remember the formula. After substituting the S.I units of each physical quantity in the formula, you will get the S.I unit of the quantity that you want to define. Remember all the derived S.I units of the physical quantities. For example newton is the derived unit of force as the S.I unit of force is \[{\text{kg}}\,{\text{m}}\,{{\text{s}}^{ - 2}}\].