A car is traveling at full speed. It crashes into the barrier, because of the negligence of the driver.
Here huge force is applied on the wall by the car in a very little time interval which we term as an impulse.
Impulse is the big force acting for a very small interval of time. It is represented by J⃗ J→.
Impulse Formula is articulated as
- Force applied is given as F
- Time interval throughout which force is applied is given as t.
Impulse can also be articulated as the rate of change of momentum.
- Mass of the body is given as m
- Velocity with which body is moving is given as v.
Velocity is articulated as
- Initial Velocity is given as vi
- Final Velocity is given as vf .
Therefore, the Impulsive force is articulated as
Impulse is articulated in Kgms-1 and Impulsive force is articulated in Newton(N).
Impulse-momentum formula is obtained from impulse-momentum theorem which states that change in momentum of an object is equal to impulse applied on the object. The formula is given as follows:
|When the mass is constant||FΔt=mΔv|
|When the mass is varying||Fdt=mdv+vdm|
As the SI unit of impulse and momentum are equal, it is given as Ns=kg.m.s-1
Below are some problems on impulse:
Problem 1: A batsman knocks back a ball straight in the direction towards the bowler without altering its initial speed of 12 m/s. If the mass of the ball is 0.15kg, calculate the impulse imparted to the ball?
vi (Initial Velocity) = 12 m/s,
vf (Final Velocity) = -12m/s,
m (mass) = 0.15kg,
J (Impulse) = ?
Impulse is articulated as
J = mvf – mvi
= m(vf – vi)
= 0.15 Kg (-12 -12) m/s
Problem 2: A golfer hits a ball of mass 45g at a speed of 40m/s. The golf club is in contact with the ball for 3 s. Compute the average force applied by the club on the ball?
Answer: m (Mass)= 0.045 kg,
vi (Initial Velocity) = 0,
vf (Final Velocity) = 40m/s,
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