To investigate how the length of a simple pendulum affects the time period for a complete swing (oscillation).
VARIABLES:.
To keep the investigation as simple as possible, only two variables are going to be changed.
Independent Variable: .
This is the length of the pendulum; it is independent, as it is not affected by other variables. .
Dependant Variable: .
This will be the time period (of one oscillation); it is dependant on the length of the pendulum.
Control Variables: .
These variables will remain the same throughout the investigation in order to ensure a fair test.
Mass of bob.
Angle of initial displacement (e).
Medium through which the bob swings (air).
Gravitational pull.
RANGE:.
The ranges of our results depend on the length of the pendulum. The shortest length possible will be determined when measuring the time period becomes highly inaccurate or even impossible. The longest length possible will be determined when the pendulum is unable to swing in a full oscillation (due to space).
Data points will be collected at regular intervals and about eight data points will be collected.
APPARATUS:.
The equipment we will use:.
Retort Stand - To hold apparatus stable.
Boss and Clamp - To hold the pendulum.
Pendulum (String tied to a bob).
Protractor - To measure the angle of initial displacement.
Ruler - To measure the length of the pendulum.
Digital Stopwatch - To record the time period.
SAFETY:.
Some safety measures will have to be taken into account. It is important that all equipment is secure so that it will not fall over, or off, during a test. Particularly the pendulum must be tied securely and the retort stand must be stable on a flat surface.
METHOD:.
After the apparatus was set up as shown before, the pendulum was set to a pre-determined length. This was measured using a ruler taking into account that the measurement should be taken from the centre of the bob upwards. After the pendulum was set, it was pulled back 45 using the protractor and released.