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Topic 3: DynamicsNewton's laws ot motion

Linear momentum {p) ol a body is known as the quantity of motion and is defined as theproduct of its mass (m) and its velocity (y).

lmpulse changes the momentum of a body. The change in momentumdetermined by calculating the area under a Force - Time graph.

Force

of a body can be

Change in momentum Ap : pz p1 = area under Force - Time graph = impulse

A body remains at rest or continues to move in a straight line wiih a unifoamveloity unless a net external Iorce acts on it to change that state.

Second Law

The rate of change of the momentum of thethe net external force acting on the body andthat force.body is directly proportionaltakes place in the direction toof

(for constant mass) (for constant velocity)Third Law For every action, there is always an equal and opposite collinear reaction-

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law of conservation of linear momentum states that whentheir total momentum before impact is equal to their totalexternalforce acts on the closed system.This law applies to every situation.

obtects of a closed system interact,momentum after impact, if no net

conventions of the velocities when dealing withrgnote 1: remember to take into account thequestions involving momentum and impulse!Note 2: this concept oI conservation of momentum is usefut in solving questions that involving {a)moving {body) bodies that undergoes cotlision/contact.

Total KE is conservedUt-U):91-Yt

lnelastic. Total KE is NOT conserved

For perfectly inelastic collision.:. The 2 bodies coalesce after impact

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