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**Dear All, would really appreciate some help with the following question - am struggling with dynamics at the minute!**

1. Homework Statement

1. Homework Statement

An 8kg mass is suspended from a grooved drum at radius r1=200mm and with a speed of 0.3m/s it drops 1.5m.

The outer radius of the drum is r2=300mm. Assume that the drum has radius of gyration k=210mm and mass 12kg and a constant frictional torque in its bearings of 3Nm. Determine the speed once it has dropped the 1.5m.

## Homework Equations

So in a hint I have been told to utilise s=r x theta and also v=wr

## The Attempt at a Solution

I attempted the following:

mgh + 1/2m(mass)v^2 + 1/2 Iw(drum)^2 = 1/2m(mass)v^2 + 1/2 Iw(drum)^2

With the left hand side being the initial velocities with the 0.3m/s.

This threw me well out (the answer is supposed to calculate to 3.01m/s.

Anyone able to help, it would greatly appreciated!

Thanks!