# How Length Affect Period of Oscillation?

Topics: Pendulum, Periodic function, Oscillation Pages: 4 (846 words) Published: August 27, 2013
Boris Tjhia 11PDe
Physics IA
Factors affecting the time period of a pendulum.
Research question: How does the length of a pendulum affect its time period? The independent variable is the length.
The dependent variable is the time.
Controlled variable is the mass of the pendulum bob.
Formula for 1 period of oscillation of a pendulum of a certain length is T=2π √lg Where l is length and g is gravity (9.81 ms-2) T2= 4π2 lg
T2= 4π2g l
Hypothesis: The longer the length of the pendulum is, the longer the time that is needed to complete 1 oscillation. The relationship will be of direct proportion. The length will be measured with a meter rule. To change the length, the string is shortened by tying it to the retort stand. The time will be measured with a stopwatch. The same pendulum bob is use throughout the experiment to make the mass a constant. The angle at which the bob is released do not affect the time period of an oscillation. I found this out by releasing the bob at different angles (30 °, 45 °,60 °) but with same length and discovered that the time periods are similar. Apparatus used: Retort Stand, String, Meter rule, Pendulum bob, Clamp, Stopwatch
Method:
To measure the time taken for 10 oscillations of the bob, we attached a string to a retort stand and tied a bob to the end of the string. The bob is then lifted to a certain height. A countdown is issued to the person releasing the bob and the person timing to reduce error. An oscillation is counted as one cycle, meaning a left swing and a right swing. Recording the time taken for 10 oscillations requires perfect synchronization between the person observing and timing as to reduce errors. For each length, 5 trials are done to obtain 5 values...