Question

A cannonball is fired with a velocity of 551 m/s. If the cannon is aimed 12° above the ground, how far away does the cannonball land? Ignore air resistance and use 9.8 m/s2 for acceleration due to gravity.

Answer 1

vertical problem first

Vi = 551 sin 12

v = Vi - 9.8 t
v = 0 at top
so
t = Vi/9.8 at top
total time in air = 2 t
= Vi/4.9

now horizontal:
u = 551 cos 12
distance = u (Vi/4.9)

Answer 2

12600