In laboratory situations, a projectile’s range can be used to determine its speed. To see how this is done, suppose a ball rolls off a horizontal table and lands 1.2m out from the edge of the table.

If the tabletop is 95cm above the floor, I figured out the ball is in the air for 0.440315285 seconds.

But what is the ball's speed as it left the table top?

Here's what I tried:

average speed = distance / time
average speed = 1.2 / 0.44.. = 2.75.. m/s

So,
average v = d/t
average v = 0.95 / 0.44 = 2.15.. m/s
final speed = 2.15.. x 2 = 4.31.. m/s

Finally,
avg speed = (intial + final) / 2

(2.75.. * 2) - 4.31.. = 1.13.. m/s = initial speed

But the answer I got is incorrect, where did I go wrong?

1 answer

Eh, never mind I figured it out myself..