Question

a object tossed into the air with an upward velocity of 22 ft/s will rise and fall according to the equation s=22t – 16t2 . at what time is the object at maximum height?

Answer 1

initial velocity u=22 ft/s
the object is at maximum height when final velocity v=0 ft/s
s=22t-16t^2
velocity at any time =ds/dt
at max. height ds/dt=0
find t ?

Answer 2

i have no clue how to solve...