# The inertia lab

## Re: The inertia lab

A formal lab is no different from the worksheet lab except there is a few other parts to add. So you should write up the formal using exactly what you did before.

I don't really know what to say for your second question... you are 100% about plugging one in for the other... you will get the correct result when solving for a.

I guess it would have to do more with the bearing since the spindle is on a bearing.

I don't really know what to say for your second question... you are 100% about plugging one in for the other... you will get the correct result when solving for a.

I guess it would have to do more with the bearing since the spindle is on a bearing.

**MattChequers**- Posts : 47

Join date : 2013-02-25

## The inertia lab

Hello! I have a couple questions about the inertia lab here...

First, in the worksheet we were asked to treat the disc as a uniform cylinder and calculate the moment of inertia, I don't know if we should keep on using that for the formal lab, because it sounds like the purpose of the worksheet question is just to let us realize that this formula isn't right and maybe we shouldn't really use it to calculate the theoretical value again?

My seconde question is how does the equation 5 in the lab manual come from? I know it is derived from equation 3 and 4, but I tried substituting one equation into the tension force of the other but it doesn't work. Can you give me a hint of how to eliminate the tension force?

Also this might sound stupid but is the frictional torque provided by the bearing or the spindle?

Thanks for answering my questions in advance!!!

First, in the worksheet we were asked to treat the disc as a uniform cylinder and calculate the moment of inertia, I don't know if we should keep on using that for the formal lab, because it sounds like the purpose of the worksheet question is just to let us realize that this formula isn't right and maybe we shouldn't really use it to calculate the theoretical value again?

My seconde question is how does the equation 5 in the lab manual come from? I know it is derived from equation 3 and 4, but I tried substituting one equation into the tension force of the other but it doesn't work. Can you give me a hint of how to eliminate the tension force?

Also this might sound stupid but is the frictional torque provided by the bearing or the spindle?

Thanks for answering my questions in advance!!!

**Zhong Li**- Posts : 9

Join date : 2013-01-10

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