Question

State whether true or false
Newton's second law gives the measure of force.
A) True
B) False

Answer 1

Newton’s law of motion describes the relationship between a body and the forces acting on it, and its motion in response to these forces. The second law of motion is extensively used to describe the situations involving a force. It gives the relationship between force and acceleration on a body.

Formula used:
$F=m\times \left( \dfrac{{{v}_{2}}-{{v}_{1}}}{{{t}_{2}}-{{t}_{1}}} \right)$
$F=ma$

Complete step-by-step solution
Newton’s second law says that an external force applied on an object is equal to the change in momentum with a change in time, or in other words, the acceleration produced by a net force on an object is directly proportional to the force. If we apply more force on the object, it will accelerate more.
Consider an object with mass $m$ is moving with a velocity ${{v}_{1}}$ at time ${{t}_{1}}$. A force $F$ is applied on the object and its velocity changes to ${{v}_{2}}$, at time ${{t}_{2}}$. Then,
$F=m\times \left( \dfrac{{{v}_{2}}-{{v}_{1}}}{{{t}_{2}}-{{t}_{1}}} \right)$
The change in velocity divided by the change in time is defined as acceleration $a$.
Then,
$F=ma$
The above equation tells us that an object subjected to an external force will accelerate and the amount of the acceleration is proportional to the amount of the force. Hence, we can say that Newton’s second law gives the measure of force.
Therefore, the answer is option A, true.

Note: This relation is only applicable for objects with constant mass. The amount of acceleration is inversely proportional to the mass of the object; for equal forces, a lighter object will experience more acceleration than a heavier object.