A body is thrown vertically upward with speed $v_0 = 20$ m/s. Find the maximum height the body reaches. Neglect air resistance; the acceleration due to gravity is $g = 10$ m/s².
At the top of the flight the speed of the body becomes zero. Use the relation between speed and height in uniformly accelerated motion:
$$v^2 = v_0^2 - 2gh$$
Setting $v = 0$ gives the maximum height formula:
$$h = \frac{v_0^2}{2g} = \frac{20^2}{2 \cdot 10} = \frac{400}{20} = 20 \text{ m}$$
$h = 20$ m