400
Give one possible likely error that would occur when using the following number of photogates to measure the instantaneous speed of a dropped ball at the "half way down point". Also give the effect the error has on the size of the measured speed.
1. With 1 photo gate at the half way down point
2. With 2 photogates (one at halfway down and one 1/4 of the way down)
1. Ball did not pass straight through the photo gate which means the speed would be too large since time difference would be too small (or diameter would be too large)
2. The instantaneous speed is getting larger so you would measure an average speed that is less than the instantaneous speed at halfway