1 A stone, of mass 0.3 kg , is thrown with a speed of \(8 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) from a point at a height of 5 metres above a horizontal surface.
- Calculate the initial kinetic energy of the stone.
- Find the kinetic energy of the stone when it hits the surface.
- Hence find the speed of the stone when it hits the surface.
- State one modelling assumption that you have made.