Page 74 - text book form physics kssm 2020

In fact, all the situations that you studied in Activity
2.14 involve a pair of forces, action and reaction. The Action and reaction force
relationship between action and reaction is explained in
Newton’s Third Law of Motion. Newton’s Third Law of
Motion states that for every action there is a reaction of equal
magnitude, but in the opposite direction. Study the examples http://bt.sasbadi.com/p4068
of situations and the explanations given below.
Increasing the magnitude of impulse by follow through action

A follow through action
after a strong kick produces
a large impulse. As a result,
the ball experiences a large
change in momentum and
moves at a high velocity.
Action on ball
Reaction
on foot Follow through action

Figure 2.55 Follow through in football

Reducing impulsive force by extending impact time

Collision causes a car to stop and experience a
change in momentum. The crumple zone of the
Reaction on car car extends the impact time during collision. As
Reaction on car
a result, the magnitude of the impulsive force
Action on object on the car is reduced.
Action on object

Photograph 2.9 Car collision test

Increasing impulsive force by reducing impact time

A pestle moving at high velocity is stopped by a hard Reaction on pestle
Reaction on pestle
mortar in a short interval of time. A large impulsive
force is produced.
Action on mortar
Action on mortar

Photograph 2.10 Using a mortar and pestle
68 2.7.1
68
2.7.1