1 A stone, of mass 0.4 kg , is thrown vertically upwards with a speed of \(8 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) from a point at a height of 6 metres above ground level.
- Calculate the initial kinetic energy of the stone.
- Show that the kinetic energy of the stone when it hits the ground is 36.3 J , correct to three significant figures.
- Hence find the speed at which the stone hits the ground.
- State one assumption that you have made.