Best way to measure rebound height of a ball accurately and precisely?

Question

We were tasked with designing an experiment based on measuring the efficiency of a bouncing ball. And so for this we would have to calculate the rebound height experimentally to obtain a quantity useable for measuring efficiency.

However, when trying to measure the height it reaches with the naked eye we encounter errors on reaction time and measurement against a piece of straight meausing tape.

Should this be first attended in a simulation under similar conditions or is there a way to measure the height the ball rebounds to with an accurate enough measurement in the physical world

One more thing how do we make sure that no force is added from the person when we drop the ball from a selected height. We did think of putting it on a piece of paper and pulling it away so it would fall untouched by us but that only created downspin and hence an incorrect measurement

Thanks for your help

Answer 1

As for measuring the rebound height, I would suggest you use a camera (make sure the camera is fixed, not hand held). Drop the ball alongside a wall with a ruler or other tape measure fixed on the wall. You may get errors due to parallax so place the camera relative to the ball and ruler so as to minimise errors caused by parallax. Note the height of the bottom of the ball at the instant it stops on the way up (with a camera you can freeze at this particular point) before it returns to the ground.

Also, to make it so that you do not impart a force or spin to the ball while dropping it, I guess the only thing you can do is drop it carefully. Hold it in between two fingers and release them simultaneously.

Also, to minimise error, do the experiment over and over so that you can average the valuses you get.