Saturday, June 6, 2015

Simple harmonic motion for a Physical Pendulum

Purpose: 
      Predict and verify the period of a solid ring and a semi-circle foam oscillating around a certain pivot.

Equipment:
      Photo-gate sensor and foam

Experiment:
    1. Set up the apparatus as the pictures show.
    2. Calculate the Inertia of the solid ring  around the pivot.
    3. Get the expression of angular acceleration and omega.
    4. Calculate the value of the period.
    5. Hanging the solid ring around the pivot, give a initial push so that the foam oscillate in a small angle. Record the period.
    6. Repeat the step with a different pivot and for the semi-circle foam.


Part A: a solid ring





Part B: a semi-circle foam








Conclusion:
     Theoretical Period of the solid ring: 0.72212 s
    Actual Period at the center of the circle:  0.721802 s
    Theoretical Period at the center of the semi-circle: 0.738501 s
    Actual Period at the center of the semi-circle:   0.739 s
    Theoretical Period  0.741046 s
    Actual Period of the semi-circle at the top0.754 s
    We successfully predict and verify the period of a solid ring and a semi-circle foam  oscillating around a certain pivot.












Friday, June 5, 2015

Lab #19 Conservation of Energy/Conservation of Angular Momentum

Purpose:
      Calculate the height that the meter stick can reach after releasing from horizontal position and hitting the clay at the lowest point by applying the concept of conservation of angular momentum and energy.

Equipment:
      meter stick, clay, video capture

Experiment:
      1. Set up the apparatus as the pictures show.
      2. Calculate the theoretical value before doing the experiment.
      3. Put a clay at the lowest point of the meter stick's path.
      4. Release the meter stick from the horizontal position with the other end pinned.
      5. Record the motion and use LogPro to measure the highest point that the meter stick reaches.
      6. Compare the actual value to the theoretical value.









Conclusion:
      The angular momentum and energy is conserved.