PASCO ME-6950 PAScar with Mass - Manual (Page 17)

012-07361B PAScar with Mass
16
If you have already done the experiment to determine the coefficient of rolling friction
for your cart for the same surface that you will be using in this experiment, you can
determine the kinetic energy of the car at the moment after impact since:
Procedure
1. Set up the system as shown in Figure 5.1. Position the car so that its plunger hangs over
the edge of the table several centimeters.
NOTE: You will need a long, horizontal table, or board for this experiment. A 3/4
inch by 1 foot by 8 foot plywood board is recommended.
2. Arrange to have a stop of some sort to insure that you always use the same pull-back
angle for the hanging meter-stick.
3. Pull the meter-stick or rod back to the pull-back angle that you have chosen and release
it, allowing it to strike the car plunger. Record the corresponding values of y and x in
Table 5.1.
4. Repeat step 3 four times for each value of y, changing it from roughly 10 to 90 cm in 10
cm increments.
5. Compute the average value of x for each value of y.
6. By interpolation, determine the location of SS1 from your data and record it below Table
5.1.
7. Using EQN-1, compute the location of SS2 and record it below Table 5.1.
8. If time permits, repeat the above after either repositioning the pivot (i.e. “choking up”) or
adding 100 grams or so at some point on the stick.
NOTE: This would add a little realism to the experiment since neither a bat nor a
tennis racket is uniform!
2
1
mv 2 = µmgx (EQN-2):