The CBL is a nice way to bring some science and technology to the classroom.

Here is a falling body problem. The object is a frisbee being dropped onto the well-protected CBR or CBL with Vernier Motion Sensor. See the results for a different experiment, a car accelerating up and down a ramp.

The Smoothed Data
0 < t (s) < 2
-2 < d (ft) < 10
Distance vs. Time
.2 < t (s) < .75
3 < d (ft) < 6

Here is the raw data after it has been smoothed. The frisbee is falling in the first 1/3 of the graph. The rest is noise after "impact".

Here is the position of our object during the fall as a function of time. It is what we would expect, resembling a parabola.

Velocity vs. Time
.2 < t s) < .75
-10 < v (ft/s) < 0
Acceleration vs. Time
.2 < t (s) < .75
-50 < a (ft/s/s) < 0

Here is the velocity vs. time graph. Notice that the object's velocity is going more and more negative as it falls. The pattern resembles the equation V(t)=Vo+at. Air resistance prevents the clear linear pattern.

Here is the acceleration vs. time graph. Notice that it is always negative, and more or less around -32 ft/s/s, earth's gravitational acceleration. The sharp incline at the end is from the frisbee hitting the ground.


A small calculator program can be written to use the TI STAT-CALC functions in order to fit the data the Position vs. Time graph. For this trial, the equation is:

d=-9.501t^2+4.479t+5.037

How does this compare with the theoretical equation for falling bodies in one dimension?