Question

Area under force-time graph gives:
A. Velocity
B. Impulse
C. Displacement
D. Kinetic energy

Answer 1

Hint: We will discuss the quantity that is given by the are under the force-time graph. We will also discuss what will be the physical significance of the quantity that is given and how it can be observed in real life events.

Complete step by step answer:

The area under the force time graph will be the quantity that is defined as the product of force applied on a body and the time period for which the said force is applied for. As you must be aware that quantity is known as impulse. Impulse is a vector quantity as it is defined as the product of a vector quantity (force) and a scalar quantity (time).
\[\vec{I}=t.\vec{F}\]
Impulse gives both the magnitude and direction of the change in linear momentum of a body due to the applied force. Impulse is very useful when a large amount of force is applied for a very small time as it can accurately give the change in linear momentum of the body. It is also used in the calculation of rocket equation using Newton’s second law of motion. We can calculate the impulse that one unit of fuel will give on burning and that value will be constant over time and can be used to derive the rocket equations.

So, the correct answer is “Option A”.

Note: When a very large force acts for a very small time, it is called impact for example a ball hitting a cricket bat. In that case it is considered that the change in momentum happened over no time. So, in such situations impulse is used to calculate the change in momentum.