A ball is thrown with an initial velocity of 120m/s at an angle of 300 above the horizontal. If it is thrown off of a cliff that is 100m high

Question

A ball is thrown with an initial velocity of 120m/s at an angle of 300 above the horizontal. If it is thrown off of a cliff that is 100m high

How long will it take to hit the ground? (ans: 13.7s)

Answer 1

You probably meant to say the angle is 30° above the horizontal, not 300.

 

h(t) = -gt²/2 + v₀sinθ t + h₀ = -4.9t² + 120sin30° t + 100

 

h(t) = -4.9t² + 60t + 100

 

Set h(t) = 0, solve the resulting quadratic equation for t, and get t = 13.7 s.