Momentum and Impulse

PHYS-TIKTOK Momentum and impulse video

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  • Momentum is defined as the product of mass and velocity. Therefore, if an object’s velocity should change (due to the application of a force on the object), then the momentum also changes.

p = m v p = momentum, a vector

m = mass of the object, a scalar

v = velocity, a vector

  • This indicates a connection between momentum and force (F).

F = rate of change of momentum

F = (mvf - mvi)/Dt

  • The product of a force and a time interval (over which that force acts) is called impulse, and is given the symbol 𝐉

𝐉 = (mvf - mvi)

Note: Both J and v are vectors, therefore x and y components are there

TikTok Problem 6:

Below figure is an overhead view of a the path taken by a car driver before and after hitting a barrier. Just before the collision, the speed of the car vi = 70 m/s along a straight line making an angle 300 with the wall. Just after the collision, the driver is traveling at a speed 30 m/s along a straight line with an angle 100 from the wall. His mass is 80 kg.

a) What is the net impulse on the driver due to the collision?

b) If the collision lasts for 14 ms, what is the magnitude of the average force on the driver during the collision?