Quadratic Motion

Question

A missile is fired from the ground level with an upward velocity of 32 ft/sec. How long will it take to return to the ground?

Answer 1

The equation of motion is s(t) = v₀t - 16t², in this case s(t)=32t-16t².

s(t) = 0 when the missile is fired and when it hits the ground, i.e. at t = 0 and when 16t=32, namely t=2.