Problem: How does the length of pendulum affect its time of oscillations? Aim: To study whether the length of pendulum will increase the time of oscillation. Hypothesis: The longer the pendulum, the longer time taken for its oscillation. Variables: a) Manipulated variable: Length of pendulum b) Responding variable: Time taken of oscillation c) Constant variable: Weight of pendulum Material and apparatus: Retort stand, string, pendulum, ruler, stopwatch .