The students want to determine how the length of the pendulum affects the period of the pendulum. Which of the following procedures should the students use to conduct the experiment?
1) Measure the length of the pendulum and record the corresponding period for each length.
2) Change the mass of the pendulum and observe the effect on the period.
3) Vary the amplitude of the pendulum and measure the corresponding period.
4) Alter the angle of release and record the effect on the period.