The above image shows the setup for the A-base moment of inertia setup.
Make sure the string is spooled on the larger pulley as pictured above. If we do, when we calculate Torque we can use a radius of 19 mm. Don’t forget to convert to the proper units for your calculations.
*Also note the eraser chunk in the picture by the sensor, make sure that doesn’t get removed as it keeps the pulleys from rubbing on each other causing error.
The rubber band pictured above on the underside of the A-base will, on rare occasions, break, if this happens there should be more up on the front desk.
The Rotational motion sensor should automatically detect when plugged in and Pasco is turned on as shown above.
We then drag a graph from the right side into the open are and set it for Angular velocity vs time.
Typically we will put 100 or 200 grams (pictured, Top of Page) as a hook weight on the string going over the pulley.
Then we start with no block masses on the rotating platform.
We let the arm start spinning as we hit record on the computer (see below) and stop the recording before the weights hit the end of the string or the ground.
The we will put a 280 gram on both sides of the rotating platform centered at 4 cm and do the experiment again. Repeat centering the masses at 8, 12, 16, 20, and 24 cm.
We will then click the drop down tab with the icon of a red line with blue dots at the top of the graph and add a linear fit line. so we can find our angular acceleration from the slope of the line.