Phil Blyghton LVM 14/2/02

GCSE ramp experiment

SECTION P: PLANNING

- Aim: To see how the angle of a ramp affects the speed of a cylinder moving down it.
### Preliminary Work

I carried out some preliminary tests to see any problems, which could occur and anything, which could be improved. I first tried timing the cylinder with a stop watch timer, although this may be slightly inaccurate because of the result being reliant on the timers reactions, we felt this to be most efficient. By setting at 5° we got a result of 1.39s. The results of the experiment with the stopwatch are shown below. The weight of the cylinder in the set of results below is 198.18g. Here, we are testing how long the cylinder takes to reach the end of the ramp – i.e. not the time it takes to completely stop

Preliminary Experiment

- After the 20° angle we found it was becoming difficult to time the cylinder and also to support the ramp. So we decided to change the range from 5°- 45° to a more suitable range of 3° - 30° and also to carry out the experiment 5 times instead of the 3 allowing us to get a better average. We had previously decided that all the cylinders should be rolled from a height of 30cm to begin with, although this could be used as a variable later on.

- One can clearly see from this set of results that a trend develops in the average time in seconds. That is to say that apparently the steeper the angle of the ramp, the less time the cylinder takes to leave the ramp. This means that, in my preliminary and most simple results there is no direct proportion between x and y as the line on the graph a) is a curve, and b) does not pass through the origin as demonstrated on the next page. However, what it does show is satisfactory enough to make a calculated prediction for the experiment.

- Hypothesis: my prediction in its most simple form is that in the experiment, the general trend of the results is that when y is big, x is smaller, and when y is small, x is bigger. This trend should stay intact through the experiment even if we change the variables quite considerably. For example, if we change the weight of the cylinder then the trend will still be as mentioned. Later, I will work out the potential energy of the cylinders using the formula E = m.g.h, where m is the mass of the cylinder, g is gravity, and h is the height of the ramp. We can work out the height of the ramp by using trigonometry. In the diagram below we know that the hypotenuse of the triangle is 30cm long, and that the angle is defined.

The equation for x is: Sin (whatever the angle is, example 10°) x hypotenuse (0.3m)