In this experiment the same clamp was used for all readings to make sure there were no miss-readings taken due to differences in the way the clamp and stand reacted to the movement of the mass. Also the spring in all readings was the same as, after all the ms and k of two different springs is going to be different and lead to different readings. The things that were varied in the experiment were, the number of slotted masses on the end of the spring and the number of oscillations of the mass to be counted.
The number of oscillations (T) will be measured using a stopcock. Which was varied to give a number between 20 and 30. To keep the number of oscillations, for every mass as similar to each other as possible. To help keep the experiment fair. So to find ms and k the following experiment was devised and carried out: A clamp and stand were used to hold a spring in position, onto which varying sizes of mass were placed. When planning the experiment, there were two methods of obtaining information about the spring, which were discussed one being the one decided upon.
The other being a way of finding out the spring constant (k), by just measuring the extension (x) of the spring, with different sized weights attached to the spring. Which would have given a straight-line graph going through the origin, where the gradient of the line would give the value k. As shown in the graph below: Graph of Force/N against Extension/m for a spring This experiment was chosen over the other one, as not only can k be found but ms can also be found. The procedure in the experiment was as follows:
1. The apparatus was set up as shown in the diagram, with the counterbalance weight in position as shown, to ensure safety by stopping the clamp and stand from falling over. 2. Amass was positioned on the spring as shown. The mass was then started oscillating and the time for a given number of oscillations was measured. The measurements were taken from a fixed fiducial point (about 4cm from the masses), with the observers eyes level with the point, to ensure there was no parallax error.
The readings were taken on the way up for one set of results and on the way down for the next set of results (as shown below). Observers took it in turn to measure the time of the oscillations to ensure any errors due to reaction times were averaged out. 3. Once one set of oscillations was recorded then another mass was positioned on the spring (after checking no damage had been done to the spring, to make sure no miss-readings were taken). Then another set of readings was taken until all the readings in the table had been filled. 4. Then the apparatus was disassembled and put safely away.