Question

an object is projected with a velocity of 10m/s from the ground level at an angle to the vertically, the total time of flight of projectile os 10secs. calculate angle when (g=10m/s) show workings

Answer 1

5 seconds up, 5 seconds down

do vertical problem first with Vi = initial velocity component up

v = Vi - g t
at top v = 0
0 = Vi - 10 t
but t = 5 seconds
so
Vi = 50 m/s

IF YOU LAUNCH AT 10 m/s, YOU CAN NOT STAY IN THE AIR TEN SECONDS!