Lab#8 Demonstration--Centripetal Acceleration vs. angular frequency

Purpose:

     To determine the relationship between centripetal acceleration and angular speed.

Measurements we will make:

• How long it takes for the disk to make some number of rotations at a range of rotational speed.

• The accelerometer reading corresponding to each rotational speed.

• Distance of the accelerometer from the center of the rotating disk. Measuring the radius by a meter stick showing is 13.8 cm.

Set up:

     Place the accelerometer on the disk. Verify that accelerometer reads 0 in the x and y-directions and -9.8 m/s^2 in the z-direction.

     Spin the disk at some speed. verify that the accelerometer reads 0 in either the x or the y direction and something in the other direction.

    Centripetal acceleration a, t0, t10 are given, we can find the angle speed omega and its square and r.

Data Treatment and Conclusion:

     The measured radius is 13.8 cm compared with the calculate radius 13.71 cm, the error is  0.07%. Those two radius are closed enough for us to determine the relationship  Centripetal Acceleration vs angular frequency is a = r*w^2.

    Because the disk is not perfect flat, it will effect the mean acceleration value. Addition, we neglect air resistance.