Yesterday we gained data for dropping balls. Height was changed and time for ball to drop measured. The relevant equation for this situation comes from one of the equations of motion giving:
s = ut + 1/2 at^2 but since u = 0, we can say that s = 1/2 at^2. If we plot a graph of s (y-axis) against t^2 (x-axis) we should get a straight line graph; the gradient of which will be equal to 1/2 a. The main area of uncertainty in this data comes from human reaction time in starting and stopping the stopclock. This is roughly 0.2s. To reduce this uncertainty, a set-up can be used with an electronic timer. When the ball-bearing is released the timer starts. When the ball-bearing hits the pad at the bottom it opens a switch which stops the electronic timer (this set-up is often used with an electromagnet to hold the steel ball in place at the top) Leave a Reply. |
Archives
December 2015
Categories |