High School Teachers at CERN WWW.CERN.CH TEACHING MATERIALS VISITING CERN LINKS & BOOKS HST

## Some easy experiments with a pendulum

 1st experiment:We need a piece of thin string and a ring… By using our watch……………………….. We make a pendulumWe measure the period of the pendulum. {If we measure the time of 10 or 20 periods the error becomes smaller. Why?) 2nd experiment:We need two strings with L2=4L1 and the same ring. How is the period related with the length of the pendulum? 3rd experiment:We need some pieces of wire, some sticks of wood or any other material, better all the same length. We put some sticks of the same material into the ring, until it is full. Is there any connection between the mass and the period? 4th experiment:Determine the acceleration due to gravity (g) in the classroom or the laboratory "exactly". (It is better to use a pendulum with L=1 m). 5th experiment:Keeping the upper point of the string of the pendulum and making small movements of our hand to right and left, by changing the frequency of the movement we can find the frequency of co-ordination.