This has to be because of the force used. Both Susie and her younger brother might have hit the ball with the same velocity, but they surely couldn't have hit it with the same force. The force with which Susie hurts it is heavier than that with which her younger brother hits it, and as such, Susie gets to fall down more pins than her brother will be able to. The ball has to have a lot of force in it for it to be able to knock off all the pins there. So basically, the more the force, the higher it's chances of hitting all the pins
The body shivers to produce energy and it uses the energy to keep it warm. The body would stop shivering when it has produced enough energy to keep it warm and the atmosphere around it has got warmer
