Required Practical 7: Simple Harmonic Motion: Mass-string System

Question 1

Describe a method to investigate the simple harmonic motion of a mass-spring system

Answer 1

1) set up apparatus
2) pull the mass hanger downwards a few cm the release
3) start the stopwatch when it passes the fiducial marker
4) stop the stopwatch after 10 complete oscillations and record this time
5) divide this time by 10 to get the time period of the system
6) add a 50g mass to the mass hanger and repeat, adding 50g each time up to 500g
7) repeat the experiment twice more to get a mean value of T for each m
8) plot a graph of T^2 against m and draw a line of best fit
9) gradient = 4pi^2 / k

Question 2

Explain safety aspects

Answer 2

• don’t attach too many masses to the spring and pit a sand box on the floor increase the masses fall off

Question 3

How can you improve experiment

Answer 3

• make sure the spring only oscillated vertically, not horizontally
• timing more oscillations reduces percentage uncertainty
• fiduciary marker should be at the centre of the oscillation
• use a motion tracker and data logger to eliminate random error