Lab 5: Conservation of Energy



Rolling Stuff Again

Consider a disk and a hoop with identical mass M and identical radius R. Suppose the objects are released from rest and allowed to roll down an incline. The incline has length $L$ and one end is raised to a height of $h$.
  1. Determine an expression for the velocity of the hoop at the bottom of the incline.
  2. Determine a similar expression for the velocity of the disk.
  3. Calculate the ratio of the two velocities.
  4. Make measurements of the velocities of the hoop and the disk at the bottom of the incline. (Take several measurements and average your results.)
  5. Does your experimental velocity ratio agree with the theoretical velocity ratio?


Inelastic collisions

Consider the "Newton Knocker" apparatus with three of the balls moved to the side, leaving two balls that can collide with each other.
  1. Release one ball from a height h_1. If the moving ball sticks to the other ball, use conservation of energy to predict how high will the two balls will go.
  2. Try the experiment, using a small piece of duct tape to make the balls stick together. Does the theory agree with experiment?


[Dave] [Physics I] [COA]

Web page maintained by dave@hornacek.coa.edu.