Momentum (Part 2)

This lesson covers:

  1. Using force to change the momentum of an object
  2. The force / momentum equations: F=ΔptF=\frac{Δp}{t}  and  F=mv−mutF=\frac{mv-mu}{t}

Which two formulae relate force to momentum?

(Select all that apply)

F = tΔp​
F = tmv−mu​
F = mv
F = Δpt

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A 20 kg object was initially moving at 10 m/s. It is now moving at 25 m/s.


Calculate the object's change in momentum.

300

kg m/s

kg m/s

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An 5 kg object was initially moving at 6 m/s. It is now moving at 20 m/s. This change took 2 s.


Calculate the magnitude of the force that caused this change.


35

N

N

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A 100 N force caused an object to increase its momentum by 50 kg m/s.


How much time did it take for this change in momentum to occur?

0.5

s

s

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Illustration of a car crashing into a wall, highlighting momentum change.

In a vehicle crash, the momentum of the people inside quickly decreases to zero.


Lengthening the time of this momentum change will decrease the forces acting upon the people in the vehicle.


Which safety features of a car aim to slow the rate at which momentum is lost?

(Select all that apply)

Safety glass

Turning indicators

Air bags

Crumple zones

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