An English physics problem A quarterback passes the football downfield at 20m/s .It leaves his hand 1.8m above the ground and is caught by a receiver 30m away at the same height What is the maximum height of the ball on its way to the receiver?

An English physics problem A quarterback passes the football downfield at 20m/s .It leaves his hand 1.8m above the ground and is caught by a receiver 30m away at the same height What is the maximum height of the ball on its way to the receiver?

The translation is as follows:
A player throws a football at a speed of 20m / s, the ball leaves his hand 1.8m above the ground, and then the ball is caught by another player 30 meters away at the same height
What is the maximum possible height of the ball?
To set the angle to do, set the angle between the speed direction and the horizontal as a
So the horizontal velocity of the ball is 20cosa, the vertical velocity is 20sina, and the direction is upward
So the time of the ball is t = s / v = 30 / 20cosa
Therefore, the vertical velocity must satisfy 20sina / g = 0.5 * 30 / 20cosa
Calculate the angle a as 0.5arcsin0.75, get the horizontal velocity, vertical velocity, movement time
So the maximum height is 0.5 * vertical velocity * movement time = 3.386m