What I will do.
I have planned an investigation to find out what sources affect the time taken for a pendulum to swing. I will do this by taking a piece of string 50 cm long and attatch a plastercine ball to the end, then I will attatch the string to a clamp which will be clamped onto a retort stand. I will then time how long it would take for 5 swings as I feel 1 swing could be 0.5 of a second out than if I do 5 swings which could only be 0.1 of a second out. I am going to do this 3 times and take down an average, then I will move the ball up 5 cm and repeat all I have done untill the string is only 5 cm long.
For this to be a Fair investigation I need to explore the following 1.
Mass of the ball.
2. Length of the string.
3. Angle of which the ball is dropped.
What I will control and what I will vary I have decided to control the mass of the ball and vary the length of the string, there is no reason for this only if I had enough time I would try both,to see the outcome. There are some areas I will not be able to control such as the wind in the room.
I will vary the length of string 5 cm's at a time as this will give me a wider range and will help me plot a graph later on.
Equipment I will need Retort stand Meter stick Clamp String