Computer Intensive Physics
Day 4

Physics 211

Spring, 1998
January 22, 1998

Create a Word file with the file name MBL-4_{your team names}

Analyzing Motion by Pulling a Cart with a Force that Does Not Change in Time:

1) Your task is to construct the system so that the empty low-friction cart
starts from rest and moves with a constant acceleration of as close to
0.75 m/s²as possible.

To complete this task, you must do the following:

*Use Science Workshop and a motion sensor to create graphs of motion as
functions of time. Display the displacement vs. time, velocity vs. time and
acceleration vs. time graphs on your computer screen at the same time.

*Hang the proper amount of mass at the end of the string and attach it to
your cart. Determine the value of the resultant acceleration of the cart as a
function of time from each of the three different graphs, using three
different software analysis tools available to you, i.e. average value, the
slope of a linear fit, and the coefficient of the quadratic term in a
polynominal fit. Collect data for two good runs. Be sure to paste a copy of
relevant graphs into your Word file. Make a table that includes the three
values of the acceleration for each good run. Then compute your best
value of the acceleration and the uncertainty in this value.

*Note: Be sure to record the total hanging mass value and the mass of the
cart.

Use Newton's Second Law to compute the force that the string must exert on the
cart to achieve the acceleration value you determined.