You can use any coordinate system you like in order to solve a projectile motion problem. to demonstrate the truth of this statement, consider a ball thrown off the top of a building with a velocity v at an angle θ with respect to the horizontal. let the building be 45.0 m tall, the initial horizontal velocity be 8.80 m/s, and the initial vertical velocity be 14.0 m/s. choose your coordinates such that the positive y-axis is upward, and the x-axis is to the right, and the origin is at the point where the ball is released. (a) with these choices, find the ball's maximum height above the ground and the time it takes to reach the maximum height. maximum height above ground m time to reach maximum height s