A ball rolls off a platform that is 5 meters above the ground. The ball's horizontal velocity as it leaves the platform is 4.8 m/s.

(a) How much time does it take for the ball to hit the ground? (Use g = 10 m/s2.)
. s

To find the time it takes for the ball to hit the ground, we can use the equation of motion for vertical motion:

s = ut + (1/2)gt^2

Where:
s = vertical distance traveled (in this case, 5 meters)
u = initial vertical velocity (in this case, 0 m/s, as the ball starts from rest on the platform)
t = time taken
g = acceleration due to gravity (in this case, 10 m/s^2)

Since the initial vertical velocity is 0 m/s and the ball falls vertically downwards, we can simplify the equation to:

s = (1/2)gt^2

Plugging in the values, we get:

5 = (1/2)(10)(t^2)

Simplifying further:

5 = 5t^2

Dividing both sides by 5:

1 = t^2

Taking the square root of both sides:

t = 1 second

Therefore, it takes 1 second for the ball to hit the ground.