A stone is projected vertically upward from ground level

PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A stone is projected vertically upward from ground level. It passes the top of a tower

20\,\text{m}

high on its way up and again

4\,\text{s}

later on its way down. Assume air resistance is negligible and take

g = 10\,\text{m\!\!}/\!\text{s}^2

. (a) Calculate the initial speed with which the stone was thrown. (b) Determine the greatest height reached by the stone above the ground.