Physics - Kinematics Question with Solution | TestHub

At the maximum height, the final velocity of the stone will be $v=0$. We are given initial velocity $u=20\text{ m/s}$ and acceleration $a=-g=-10{\text{ m/s}}^2$ (taking upward as positive). Using the equation$v^2=u^2+2aS$:$$0^2=(20{)}^2+2(-10)S$$ $$0=400-20S⟹20S=400⟹S=20\text{ m}$$