For my experiment I am going to be investigating gravity by freefall by dropping a ball bearing onto a micro switch (pressure pad) from different heights and recording the time taken for it to land. Plan: I have chosen to measure gravity by freefall using a range of apparatus. I decided to use timing electronics linked to a micro switch pad with a ball bearing release mechanism to provide the most accurate results possible.

I am going to achieve my aim by having a ball bearing in between two metal plates and when the potential difference is lost between the two plates (when ball is dropped) the timer will begin until the pressure pad is hit. Accuracy is key in getting the correct results, I need to be working towards proving that g = 9. 81… metres per second. I am going to give room for error by taking +/- 0. 1cm for the dropping height as well as maintaining the time to 3dp. I am going to drop my ball bearing from heights ranging from 100cm – 10cm in increments of 10cm +/- 0.

1cm and I will be doing this 3 times to increase the reliability of my results by taking an average of the three. The equation I’m going to use to plot as the x-axis against the distance fallen will be (S = ut + 1/2 ati?? ) which will relate to: (y = mx + c) where ut = c so that can be excluded as ut = 0 and mx = 1/2ati?? therefore x = 1/2ti?? and m = a so the x-axis will be plotted to 1/2ti?? where t is the time I predict that there will be a constant gradient of around 9. 81ms-i??

between the height being dropped and 1/2ti?? helping me prove “g” by freefall. I also predict that the graph should show a trend in the distance fallen +/- 0. 1cm to 1/2ti?? due to the gradient remaining a constant. My predicted graph for my result Prior to my main experiment I did a preliminary experiment to see how many final test proved in the accuracy of “g” by freefall, as well as giving me an idea of what to expect for my results and help me in deciding what apparatus to use.

Apparatus: * Stopwatch * Ticker Timer * Ruler * Clamp * Boss * Retort Stand As it’s a very simple experiment the set up of the circuit will be very simple too the ticker timer will be placed on a clamp attached to a retort stand and the ticker timer will have a weight attacked to a 5cm strip of paper and the ticket timer will punch holes in the paper every 0. 02s as it falls, so all there is to do is count the dots for each height and times it by 0. 02.