Hi guys. So recently we conducted an experiment involving moment of inertia and

Question

Hi guys. So recently we conducted an experiment involving moment of inertia and rotating systems. Before I ask the question, here is the context to the problem. The system in this case consists of a rotating disc that can be set in motion by a falling cylindrical block attached to the hub of the disc by a length of string (see below - note that the photos show the additional weights attached to the disc):

Can you also mention some examples of real world application involving moment of inertia and rotating disks, etc?

Explanation / Answer

So for the fiest part. It is correct that you will have to plot total inertia wrt radius as the equation we have is.

Io + MR^2 = I , here as Io is the inertia of the disc ,it will remain constant. So we can imagine this eqaution as

Y = M X + C , where I is Y, X is R^2 and Io is C. hence linearising this eqaution will give the slope as M

2 . We have to attach two weights to bring the system at equilibrium , because one weight will create a net torque which will accelerate the system. Attaching them at same radius will make the torque due to their weight as zero.

Real life examples- Opening a door from a point closer to the hinge is tougher than opening it from the other end because torque applied due to the force given by you is less due to the distance from the axis is lesser when applied near the hinge.

If you are rotating in a chair , your rotation speed goes down if you strech your hands wide, this is due to increase in moment of inertia.

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.