Lab #9 Centripetal Force Motor

Purpose: We are meant to find the relationship between theta and omega of the apparatus.

 We accomplish this by recording the time the rubber stopper makes a rotation and measure the height of the stopper from the ground (h).

However, before we can start any of that we would have to record the radius, length of the string (L) and height of the apparatus (H).
L= 1.645m
R=.98m
H=2m

Once all measurements are gathered we had to come up with our formulas for theta and time before we started recording times and finding h. Theta was found by using a right triangle with the hypotenuse as L and the height as H-h. Then we figured out time by drawing a force diagram of the rubber stopper and solving for omega and replacing to solve for time.

After the formulas were derived we had to start our actual experiment. The object of this part was to record the time of ten rotations. Then have a ring stand with a horizontal piece of paper tap the bottom of the stopper in order to get h. We did this 6 times at different speeds in order to get different angles.


After all is recorded we plugged everything into our previously derived formulas to get the theta and time of each test. However, to make sense of everything gathered and collected we charted all of the calculated thetas and times.

This graph represents the actual and theoretical times we figured out. By figuring out the best fit line of the graph we can see how accurate our data was.