How To Find Max Height Of Projectile. Get the initial velocity of the object. At the cannonball’s maximum height, its vertical velocity will be zero, and then it will head down to earth again.

Key fact to remember for any projectile when it reaches maximum height is that the vertical component of the velocity is zero. I calculate the maximum height and the range of the projectile motion. When you launch a projectile at an angle θ from the horizontal, the initial velocity of the projectile will have a vertical and a horizontal component.