Accelerometer on a turntable

A video of an accelerometer on a turntable at 78, 45 and 33rpm is synched to acceleration-time data. The data in the video can be used to calculate the position of the accelerometer chip within the accelerometer. A photo at the end shows the position of the accelerometer chip given in the manual for the accelerometer.
The video can also be used an an opportunity for students to predict the directions of forces (and therefore accelerations) they expect to see. The brief positive and negative accelerations in the direction tangent to the radius (separated by zero acceleration when angular velocity is constant) are useful discussion points, providiing many students with a way to make sense of their conviction that there should be a force in the direction of motion - it is clear from the data that there is a force in the direction of motion when the accelerometer is increasing rotational speed, and a force in the direction opposite to motion when it is decreasing its speed, and no force in the direction of motion when it is moving at constant speed.