# Investigation to find a value of g using the oscillations of a spiral spring.

AS / A2 Physics Coursework

Name Nicola Morris Teacher Mrs. Farrow

Date February 2002

Title / Aim

Investigation to find a value of g using the oscillations of a spiral spring.

Diagram

A2b partial

A4c complete + labelled

List of apparatus

Clamp Stand and G clamp

Metre Ruler (0-100 cm) +/- 0.1 cm

Slotted mass and mass hanger (0-1kg added in 0.1kg masses)

Stopwatch =/- 0.01 seconds

Spiral Spring

Fiducial Mark

Blu-tack

Pointer Flag

A2d some

A4d comprehensive

A6d full specification

Variables involved (constant and changing)

There are two types of variable within my experiment - dependant and independent. In the static experiment, the load is independent, kg, and the extension is dependant, m. In the dynamic experiment, there is the time period, seconds, which is dependant, and the load, kg, which is independent.

F=ke, if k is kept constant. If k is kept constant, then my graph will show a straight line through the origin. This shows that F ? extension.

In my dynamic experiment, T 2 = 4? 2 m/k . This shows that again, if k is kept constant, my graph will be a straight line, and T 2 ? mass. To ensure that k is kept constant, I always used the same spring and same masses.

My range of variables was so that, my mass didn't exceed 0.7kg, as from my preliminary experiments, I knew that this wouldn't exceed the elastic limit. I took 7 results for both experiments. The preliminary tests, were to test the spring, and see how far it could stretch before exceeding its elastic limit. I loaded the spring up, with slotted masses. One at a time, until the spring broke. I measured the extension for each load, and plotted a graph from my results. I could see on my graph, that where the line was straight, the spring hadn't exceeded its elastic limit. Where the graph began to curve was where it had exceeded its limit.

A4b one appropriate

A6a one fixed variable

Method

Static Experiment

I set up the equipment as shown in the diagram. I hung the mass hanger onto the spring, with a pointer to give a clear indication of its position against the ruler. The pointer was good because it reduced parallax. I kept the pointer in the same place on the mass hanger, so the measurements of extension were fair each time. When I hung my mass hanger on, I looked at the metre ruler, and found my scale measurement. This was the measurement I ...