A bullet moves east at a velocity of 480 m∙s-1. It hits a wooden block that is fixed to the floor. The bullet takes 0,01 s to move through the stationary block and emerges from the block at a velocity of 80 m∙s-1 east. See the diagram below.
Ignore the effects of air resistance.
Consider the block-bullet system as an isolated system.
![](https://axiumlearn.co.za/wp-content/uploads/2021/10/image-80.png)
4.1 Explain what is meant by an isolated system as used in Physics. (4)
The magnitude of the momentum of the bullet before it enters the block is 24 kg∙m∙s-1.
4.2 Calculate the:
4.2.1 Mass of the bullet (3)
4.2.2 Average net A force exerted by the wooden block on the bullet (5)
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