posted by Jim .
In class, we completed a lab dealing with the range of a projectile. First, we dropped a metal ball down an inclined channel followed by a horizontal channel. We timed the ball on the horizontal channel and used this time and the channel length to find horizontal velocity of the ball. Then, we used the vertical distance from the tabletop to the floor to find the vertical time (the contraption was set up on a table. eventually we let the ball drop from the table, like a projectile, and predicted its landing point, its range). Finally, we used the horizontal velocity and the vertical time to find the displacement of the ball.
My question is why does this experiment support the premise that the horizontal and vertical components of motion do not affect each other?
The time for the ball to hit the floor would have been independent of the speed of the ball on the horizontal channel. The vertical fall time depends only upon the distance that it falls, if the intial horizontal velocity component is zero.