a child throws a tennis ball vertically upwards at 7.7 m/s from ground level. assuming that no resistance force act on the ball, so that it move only under the influence gravity (9.81 m/s-²), what is the maximum heightin the tennis ball reaches

Answer 1

well,
h(t) = 7.7t - 4.9t^2
max height is reached at t = -b/2a = 7.7/9.8
so plug that in to find h there.