Hypothetically, if you were standing on the balcony of an apartment on the 10th level of building and you throw a ball at 30° above the horizontal away from the building at 4.5m/s, how far from the building would the ball land?. The height from which the ball is thrown is approximately 30m.

Answer 1

Hypothetically, do you ignore wind and air resistance?

Initial vertical velocity: 4.5sin30

go to the height equation:
hf=hi+InitialVelocityvertical*t-1/2 g t^2
hf=-30, hi=0 solve for time in air, t.

distance equation
horizonaldistance= 4.5cos30*timeinair
Hypothetically, with no air friction or force.

Answer 2

First of all your initial vertical velocity is not 4.5 m/s.
it is Viy= 4.5 * sin(30)
and your horizontal = 4.5 * cos(30)