Grade 12U Physics

Collision Lab

Instructions:

A formal report is not required. Hand-in a cover page with your name and/or your partner’s name, due date and your instructor's name. Other than the cover page, your report must be in your own handwriting, not computer generated. Plagiarism will result in a zero for all parties concerned. For calculations, all steps must be show in a neat and logical manner. Explanations must be concise and in complete sentences. Marks will be deducted for missing steps, missing units and incorrect # of significant digits. Hand-in this question booklet with your report.

  1. Go to lesson #5 on Mr. Simpson’s moodle and look up “Physics simulations”. Click on URL Click on “Physlets in the first semester”. On the left margin, scroll down to “Momentum”. Click on “Elastic and inelastic collisions”. Assume three-digit accuracy for all data given. Click on “elastic” collision and “m1 =5m2”.

Note m1 = 2.00 kg and m2 = 0.400 kg. Note the red dot represents the center of mass of the system of the two carts. Press play for 1.50 seconds and then pause. Reset if you want to redo the experiment.

  1. Sketch and label the graphs of Momentum vs time and Kinetic Energy vs time.
  2. Use your graphical data to verify that the collision is elastic: i.e. momentum and kinetic energy of the system is conserved before and after the collision. Show all steps in your verification.
  3. Read about “reporting data involving measurements” in the new textbook p 694 or “error analysis in experimentation” in the old textbook p755. Using your reading as a guide, read the following quantities from the graph or given info, state the assumed uncertainty in the quantity, and then convert these uncertainties to percentage uncertainties. Be sure to show the steps in the conversions.

a)Momentum of m1 after the collision

b)Momentum of m2 after the collision

c)The mass of m1

d)The mass of m2

  1. Using data from the graph and showing all formulas and steps, calculate the velocity of each mass after the collision. Along with your velocity calculation for each mass, determine the percentage uncertainty and uncertainty in each of your answers. Explain clearly in words how you obtained these answers.
  2. You learned two head-on elastic collision equations in class. Using high school algebra and showing and explaining all steps, derive these equations from conservation of system momentum and system kinetic energy before and after the collision.
  3. Use the two head-on elastic collision equations learned in class, predict the velocities of each mass after the collisions and compare your predictions with your answers in Q#5.
  4. Now press reset and click “m1 =5m2” under k = 0 (totally or perfectly inelastic collision). Draw and label the momentum and kinetic energy vs time graphs of this collision. Verify that the system momentum is conserved but not the system kinetic energy before and after the collision.
  5. Showing all steps and outlining your reasoning in words, determine how many Joules of energy is lost to the system during the collision simulated in q#8.