Question

A ball rolls horizontally off a table of height 0.6 m with a speed of 9 m/s. How long does it take the ball to reach the ground?

Answer 1

The speed at which it rolls is a red herring. All we need to know is the initial vertical velocity, which is 0, and the height, which is 0.6 meters. For uniform acceleration from a standing start, \[h = \frac{1}{2}gt^2\]where \(g=9.8 \text{ m}/\text{s}^2\) will give us the time \(t\) it takes for the ball to fall \(h=0.6 \text{ m}\)

I'm guessing that maybe there's another part of this problem which asks how far from the edge of the table the ball lands. We can find that by multiplying the horizontal speed (9 m/s) by the time it takes to fall.