College math

Question

A cannon ball is launched into the air with an upward velocity of 396 feet per second, from a 11-foot tall cannon. The height h of the cannon ball after t seconds can be found using the equation
h=−16t^2+396t+11

Approximately how long will it take for the cannon ball to be 384 feet high? Round answers to the nearest tenth if necessary.



How long long will it take to hit the ground?

Answer 1

384=-16t² + 396t + 11

0 =-16t²  +396t - 373

Use the quadratic formula to get 2 answers: .980781 and 23.769215 which means it hits 384 ft on the up shot and when falling back down