UNIFORM MOTION LAB CP1
Name: ___________________
Partners: _________________
_________________
Purpose:
Equipment:
Procedure:
1. Use the strip timers to record the motion of two carts as they roll freely across the floor. Give them a push, let
them roll, and catch them on the other side. One should be fast and the other slow. Label the beginning of the
tape as either fast or slow.
1. Place both tapes on a table, and on each, measure the distance of each dot from the starting point and record
these distances in a data table. Measure the dots until the cart is no longer moving freely, but do not exceed
100 dots on each tape. Save the tape.
2. In Excel, make a position vs. time graph, placing both trials on the same graph. Position is in “cm” and time
in “number of dots.”
3. Draw best-fit lines for each major straight section for each set of data.
4. Calculate the slope of each best-fit line. Be sure to show your slope calculations on the graph paper so that it
is easy to see exactly, which points you used and how you did the calculation.
5. Convert any units of “numbers-of-dots” to “seconds” using the timer calibration given by your teacher. Do
this conversion only when doing slope calculations.
Questions, Analysis & Conclusions:
1. Tape the paper tapes next to each other on the table. Compare the spacing of the dots for when they were
rolling freely across the table. Which trial had a greater spacing between dots and what does this mean?
2. What is the motion of the cart if the best-fit line is straight? What does a steep line mean? What does a
shallow line mean? What if it’s flat?
3. What are your slope values for the trials and what do these values tell us about the carts?
4. In places where the best-fit line on the graph is a curve, what does a curved line of data mean? What is
happening if the curve of the best-fit line is upward (it is becoming steeper)? What if it is curving downward
(becoming flatter)?
5. Select a point on a curved section of the plot of either of your graphs, draw a tangent at this point, and
calculate the slope of the tangent. Again, show all calculations clearly on the graph paper. What does this
slope number tell us?
6. Write an equation for the line for each straight-line graph (estimate the values for the y-intercepts). Try to
explain what these equations represent and to which Physics formula they correspond.
For your Lab Report:

Make sure graphs are completely labeled.

Make sure slope calculations contain units.

Answer the questions in complete sentences, and make them long enough to support your conclusions.