# Thread: Hard Pre-calc problem need help!!!

1. ## Hard Pre-calc problem need help!!!

A stone is thrown from the top of a building which is 50 ft high at a speed of 30 m/s and a angle of 30 degrees above the horizon

a second stone is thrown towards the first but this building is 100 ft high and the stone is thrown at 20 m/s and angle is 45 degrees

the stones hit the ground at the same place how far apart are the buildings?

thank you.

2. Originally Posted by Pre-Calc
A stone is thrown from the top of a building which is 50 ft high at a speed of 30 m/s and a angle of 30 degrees above the horizon

a second stone is thrown towards the first but this building is 100 ft high and the stone is thrown at 20 m/s and angle is 45 degrees

the stones hit the ground at the same place how far apart are the buildings?

$\displaystyle \Delta y = v_{yo} t - \frac{1}{2}gt^2$

start by using this equation to find the elapsed time of motion for each projectile.

$\displaystyle \Delta x = v_x t$

finish by determining $\displaystyle \Delta x$ for both projectiles ... distance between the buildings will be $\displaystyle \Delta x_1 + \Delta x_2$