A bullet is fired vertically upward from a gun and reaches a height of 7000 ft. Find its initial velocity. How long does it take to reach its maximum height? How long is it in flight?

Answer 1

at the top, vertical velocity is zero
h=vi*t-1/2 g t^2
7000=vi*t-16t^2

this is a quadratic, solve for time.

Initial KE=final PE
1/2 m v^2=mgh solve for v, the initial velocity

how long is the flight? Twice the time to the top.