Explain the term
Impulse .discuss some of the application of this concept
Answers
From Newton's second law : External force is equal to the rate of change in momentum. So, we can write,
F = (mv - mu)/t
F x t = mv - mu
External force x time (taken to change momentum from mu to mv) is called the Impulse.
Application :
Think of a car accident. A car hits a wall. If you want to calculate the force applied on the car as result of the impact with the wall. You want to calculate the Impulse force.
You will need he mass of the car (m) , velocity of the car before the impact (u) and the time taken (t) to stop (Final velocity) the car after hitting the wall.
Impulse: The product of the force exerted on a body and the time interval of the force is defined as an impulse.
Impulse is a vector quantity and so it is directed.
It is directly related to momentum.
Impulse = Force * Time
The unit of impulse is kg.
Applications:
- To define the Newton's second law of motion.
- When a ball is caught, the hands are lowered so that the time increases and the force of impact decreases.
- Shock absorbers used in vehicles also increase the time and so it reduces the force of impact.
- Air bags in automobiles.
- Riding of a punch in boxing.