Question

A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H of 32.0 m above sea level, directed at an angle θ above the horizontal with an unknown speed v0.
The projectile remains in flight for 6.00 seconds and travels a horizontal distance D of 161.0 m. Assuming that air friction can be neglected, calculate the value of the angle θ.
Calculate the speed at which the rock is launched.

Answer 1

h = Hi + Vi t - 4.9 t^2
0 = 32 + Vi (6) - 4.9(36)
6 Vi = 144.4
so
Vi = 24.1 m/s up

u = 161/6 = 26.8 horizontal

tan theta = Vi/u

Vo = sqrt (u^2 + Vi^2)