Answer to Question #343819 in Molecular Physics | Thermodynamics for kate

Question

A boy throws a baseball onto a roof and it rolls back down and off the roof with a speed of 3.80 m/s. If the roof is pitched at 24.0° below the horizon and the roof edge is 3.30 m above the ground, find the time the baseball spends in the air and the horizontal distance from the roof edge to the point where the baseball lands on the ground.

Answer 1

$$y=y_0-v_0\sin\theta t-gt^2/2\\ y=3.30-1.55 t-4.9t^2$$

At the grounf level

$$y=0\\ 3.30-1.55 t-4.9t^2=0$$

The time of flight

$$t=0.678\:\rm s$$

The horizontal distance

$$R=v_0\cos\theta t\\ =3.80\cos 24.0^\circ*0.678=2.35\:\rm m$$