Question

Define impulse acting on a body ?

Answer 1

Hint: The overall effect of force on the motion of a body is known as the impulse. Its value is the product of the applied force and the time interval during which the force is applied. When a force is applied for a short time period \['dt,\] the result is a force impulse.

Complete answer:
In classical mechanics, the integral of a force, \[F\] , over the time interval, \[t\] , over which it acts is called impulse (symbolised by \[J\]or \[Imp\] ). In the same way that force is a vector quantity, so is impulse. When an item receives an impulse, it experiences a vector change in its linear momentum in the opposite direction. The Newton second \[\left( {Ns} \right)\] is the SI unit of impulse, while the kilogramme metre per second \[\left( {kgm/s} \right)\] is the dimensionally equivalent unit of momentum.

For as long as it acts, a resultant force causes acceleration and a change in the velocity of the body. As a result, a resulting force delivered over a longer time creates a larger change in linear momentum than a force delivered quickly: the change in momentum equals the sum of the average force and duration. A little force applied for a long time, on the other hand, causes the same change in momentum—the same impulse—as a bigger force applied for a short time.
$J = {F_{average}}\left( {{t_2} - {t_1}} \right)$
The integral of the resulting force \[\left( F \right)\] with respect to time is the impulse:
$J = \int {F\,dt} $.
Momentum and impulse have the same units and dimensions \[\left( {ML{T^{ - 1}}} \right)\] .

Note:A fast-acting force or impact is often referred to as "impulse." This type of impulse is frequently idealised so that the force's change in momentum occurs with no change in time. This is a significant alteration that is not physically conceivable. This model, on the other hand, is useful for calculating the impacts of perfect collisions (such as in game physics engines). In addition, the term "total impulse" is often used in rocketry and is regarded synonymous with "impulse."