4. Momentum and Impulse

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Change of momentum relates to the forces acting on the vehicle of the driver

4.1 - Momentum

Define momentum as: p=mv

Momentum is the product of mass and velocity

It is a vector quantity with both magnitude and direction

The magnitude can be determined by the formula p=mv

The direction of the momentum is the same distance as the direction of the velocity

Momentum is also related to inertia, as an object with greater momentum will be more difficult to stop or change direction

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4.2 - Define impulse as the product of force and time

Impulse is the product of the net force acting and the time for which it acts

It is also the change in momentum

The net force of an object can be plotted against time

The area under the curve for a force-time graph is the impulse, since I = Ft

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4.3 - Explain why momentum is conserved in terms of Newton's Third Law of Motion

The law of conservation of momentum states that during a collision, the total momentum for a closed system is conserved so that the total momentum before and after the collision are unchanged

Total initial momentum = Total final momentum

This is the direct result of Newton's Third Law of Motion

During a collision, even though the total momentum is conserved, total kinetic energy may not necessarily be conserved