Projectile height with time

Question

A ball is thrown in the air with a velocity of 95ft/s. Use the projectile formula h=-16t^2+vot to determine at what time in seconds the ball is at height of 120ft.

Answer 1

If you plug the values given into the equation, you get

120=-16^t2+95t

Subtract 120 from both sides:

0=-16^t2+95t-120

Solve using the quadratic equation:

t=1.82 second and t=4.11 seconds