Impulse and Momentum
Momentum
Momentum is inertia in motion
Example 1
The first manmade satellite, Sputnik I, had a mass of 83.6 kg and a momentum of
6.63 X 105 kg m/s. What was the satellite’s speed?
Impulse
When objects collide they experience a change in velocity
which causes a change in the object’s momentum.
A change is momentum is known as Impulse
A change in velocity is the result of acceleration which
affects force so Impulse is also related to force
Example 2
A 75 kg man is involved in a car accident. He was initially traveling at 65 km/hr
when he hit a large truck.
(a) If he had no air bag in his car and he came to rest against the steering
wheel in 0.05 s, determine how much force was exerted on his body
(b) If he did have an airbag that inflated and deflated correctly, bringing him
to rest over a time of 0.78 s, determine how much force was exerted on his
body.
Example 3
A 0.105 kg hockey puck is traveling at 12 m/s when it is struck by a stick. As a
result, the puck travels at 15 m/s in the opposite direction. If the contact
between the stick and puck lasted 0.05 s, what was the force?
Example 4
A varying force is exerted on an object of mass 2 kg that is initially at rest as
shown in the graph below.
What is the impulse during the 1st 20 sec?
What is the velocity at t = 20 sec?
What is the average force exerted over the 20 sec?
What is the impulse imparted to the object over the whole time?