Fall2023 Moment of Inertia Lab Online-1

From the free body diagram and force summation equations of the system, we see that the tension in the string will be: T = m h g − m h a T = m h ( g − a T ) Inserting this for the tension, as well as the known equations for torque and angular acceleration, gives us: I = r∙m h ( g − a T ) a T r = r 2 ∙m h ( g a T − a T a T ) I = r 2 ∙m h ( g a T − 1 ) This final equation gives the experimental value for the moment of inertia of the rigid body, where here r is the radius of the horizontal pulley the rigid body is attached to. (Please note that in constructing this equation we assumed that the moment of inertia of the two pulleys are so small compared to the moment inertia of the rigid body’s that they were simply ignored.) Setup 1. Go to the following website: https://phet.colorado.edu/en/simulations/torque 2. You should now see the following: 4