Energy of a pendulum

gIn this activity you will examine conservation of energy using a pendulum, by measuring the speed of a pendulum when released from different heights

You will be usng Tracker to analyse the video of a slow moving pendulum

Pre-lab questions

    1. Annotate the pendulum above to show the change in height, point of max velocity and point of zero velocity.

    2. Identify the point on the diagram where the gravitational potential is at a max

    3. Identify the point on the diagram where the kinetic energy is a maximum

    4. Explain where the kinetic energy comes from?

    5. Using the relationships for gravitational potential energy and kinetic energy, give an expression for the maximum velocity.

Equipment

String, make a slip knot on each end

Slotted masses

Retort stands x 2

    1. Set up a pendulum of approx 30cm in length, with 250g hanging as the bob.

    2. Lift the pendulum approximately 3 cm from the resting height and release when ready to video

    3. Repeat for different heights

Results

Mass of the bob: kg

Analysis

    1. Calculate the gravitational and the kinetic energy for each test

    2. How does the gravitational and kinetic energy compare in each test. Is this what you would expect? Explain.

  1. Is there any relationship between the variation in the two measures and the height? Can you explain this?