Data from AP Physics students at Berkeley High School,
Berkeley CA courtesy of Richard White.
Students rolled ball bearings down 3-meter steel tracks. They released
them from specific positions (50 cm, 1 m, 1.5 m, etc.) and timed
how long it took the bearings to get to the bottom. Timing was with
stopwatches, generally three students timing per trial. They did
about three trials at each height.
The purpose was to explore acceleration, and find the acceleration
of the balls on the track.
Angle is the angle of the track in degrees (measured
with a protractor).
distance is in meters, the distance from the ball
release to the end of the track.
trial is the trial number, i.e., the three measurements
for trial 1 were all the same roll.
time is the time in seconds
recorder is the initial of the person wielding
the stopwatch for that measurement. Evidently this group got tired
of recording that!
Questions and tasks
The data look more or less linear. How do you know that they are
What relationship do you expect between distance and time if there
is uniform acceletarion?
In this experiment, which goes on the horizontal axis, distance
or time? Why?
What was the largest and smallest acceleration at each angle that
is consistent with the data?
How do you deal with the spread in the data?
What do you think -- are these data consistent with uniform acceleration?