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4.1 What is meant by an isolated system in physics? (2)
During an experiment, a rocket of unknown mass is mounted on a toy cart of mass 20 kg. The cart-rocket combination moves at a constant speed of 2,5 m∙s-1 along a horizontal floor.
At a certain instant, the rocket is fired horizontally in the direction of motion at a speed of 30 m∙s-1. As a result, the cart slows down to a speed of 0,6 m∙s-1, as shown in the diagram below.
Ignore frictional effects.
4.2 Use relevant physics principles to explain why the firing of the rocket will slow down the cart. (2)
4.3 Calculate the mass of the rocket at the instant the rocket was fired from the toy cart. (5)
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