# Parabola Experiment

### Hypothesis

The hypothesis was that the ball would fall in a parabola such as the
ones that Galileo described. If that was indeed the case, then we would
be able to assume that Galileo had indeed performed these experiments.

### Apparatus

Inclined Plane
Camera Stand

Steel Ball Bearing

Butcher paper

Carbon Paper

Tape Measure

Boxes

### Procedure

1. Build inclined plane. (See inclined
plane experiment.)
2. Find the angle of the plane.

3. Set up the paper on which the ball will fall.

4. Measure the distances that the ball would roll along the plane and the
height the ball would fall after leaving the inclined plane.

5. Roll the ball five times from each distance, using the carbon paper to
mark the impact location.

6. For trial two, we used a different angle, and otherwise did everything
else the same.

7. For the parabola tracing, we collected boxes and stacked them up. We
let the ball roll five times for each height, marking the distances on
the same sheet of paper.

8. We measured the distances on the papers and analyzed the data.

### Problems

We attempted to build a deflector made of Play Doh at the bottom of the
inclined plane. However, trial runs showed that the ball did not roll
along the deflector, but instead jumped over it. We hypothesize that this
is because Galileo used angles of no less than 30 degrees, while our
greatest angle was 13.4 degrees. At a larger angle, the downward
component of motion of the ball is sufficient to keep it in place along
the deflector. At our angle, the downward component of the motion was not
sufficient to do so.

### Links

Last Revised April 17, 1995.

Martha Turner, Sharmaine Jennings

mat@rice.edu

vanese@rice.edu