Abaseball rolls off a 0.70 m high desk and strikes the floor 0.25m away from the base of the desk. how fast was the ball rolling?i don't understand this : (

We can calculate the time it takes for the ball to fall to the floor. y = (1/2) a t^2 t = sqrt { 2y / g } t = sqrt { (2) (0.70 m) / (9.80 m/s^2) } t = 0.378 seconds In a time of 0.378 seconds, the ball traveled a horizontal distance of 0.25 meters. We can find the horizontal speed when the ball was rolling on the desk. v = d / t v = 0.25 m / 0.378 s v = 0.66 m/s The ball was rolling at a speed of 0.66 m/s when it was rolling on the desk.