Aim:
To determine if the length of a pendulum affects its period, (T), and compare the theoretical value of (T) to the experimental value.
Background Information:
A simple pendulum is one that can be considered to be a point mass suspended from a string or rod of negligible mass. It is a resonant system with a single resonant frequency. For small amplitudes, the period of such a pendulum can be approximated by:
Where
Laws of a simple Pendulum
▪ The period of a simple pendulum of constant length is independent of its mass, size, shape or material.
▪ The period of a simple pendulum is independent of the amplitude of oscillation, provided it is small.
▪ The period of a pendulum is directly proportional to the square root of the length of the pendulum.
▪ The period of a simple pendulum is inversely proportional to the square root of acceleration due to gravity.
Hypothesis:
It is hypothesised that as the length of the pendulum increases, the period (T), will also increase. Providing there is a constant angle of release (or amplitude) as the length of pendulum increases, the distance travelled by the point of measurement ( or ‘bob’) will increase. Hence the period increases.
Apparatus:
- 3 Large nails
- Large protractor
- Tape measure
- String 2m
- 500g Mass (pendulum bob)
- Stopwatch
- Spirit Level and set square
Variables:
Independent Variable – The length of the string
Dependent Variable – The time it takes for the pendulum to oscillate
Controlled Variables – The mass of the bob
– The amplitude
– The string, changed in length
– Controlled environment
Method:
1) A table was drawn that allowed for recordings of raw data – 3 trials of 6 independent variables.
2) The equipment was set up as shown in the diagram...