March 3, 2003
Today we will continue our focus on the scientific method.
We will measure the acceleration of a cart on an inclined plane
connected to mass hanging from a pulley. We will measure the acceleration
as a function of the mass of the cart, the mass on the pulley,
and the angle of inclination. We have studied the 3 extreme cases
of this experiment already in previous measurements:
- The Atwood machine (experiment P13): a = (M1 - M2)*g/(M1
- The acceleration of a cart (experiment P09): a = m*g/(m +
- The acceleration of a cart down an inclined plane (experiment
P04): a = g*sin(theta)
In todays experiment we will repeat experiment P09, except
with the following differences:
- the track will be tilted
- instead of using the smart pulley we will use the photogate
to measure the velocity of the cart
To predict the relation between the acceleration of the cart
and the masses involved and the angle of inclination of the track,
you will carry out a series of measurements in which these 3 parameters
are being changed.
- To start this experiment, discuss with your partner why the three experiments
listed above are extreme cases of the experiment you will be carrying out
- Based on the known dependence of the acceleration in these two extreme cases,
make a prediction for the acceleration of the cart up or down the incline
as function of the angle of inclinations, the mass of the cart, and the mass
hanging on the pulley.
- Open experiment
P09a "Up and Down the Incline" in your handout folder. The instructions
for the measurement can be found in the "Experiments Notes" window
and on the WEB (under class note: Force and Motion).
- After carrying out each sequence of measurements in P09a, compare the results
with the predictions you made earlier.
At the end of the class I would like to receive from each of you the following
- Summary of your observations (use the table format that you can find as
part of the WEB pages describing this experiment).
- Your predicted relation between the measured acceleration and the masses
connected to the pulley.
- A comparison between the predictions made on the basis of your theoretical
relation and the measured values.
© Frank L. H.
Wolfs, University of Rochester, Rochester, NY 14627, USA
Last updated on
Monday, March 3, 2003 10:34