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## Homework Statement

A mass of 0.5kg is suspended from a flywheel, if the mass is released from rest and falls a distance of 0.5m in 1.5s calculate:

A, the Linear acceleration of the mass

B, the angular acceleration of the wheel

C, the tension in the rope

D, the friction torque.

Known information

Mass of wheel 3 kg Mp

Outside radius of wheel 0.3m

Radius of gyration 0.212 m

## Homework Equations

## The Attempt at a Solution

A,

mg - T = ma

TR=Ia/R

mg-(Ia/R^2) = ma

a= mg/(m+(I/R^2))

Swapping I out for I=(MpR^2)/2

gives

a=mg/(m+((MpR^2)/R^2)

a=mg/(m+(Mp/2)

a=2.4525

2.45 m/sec^-2

B,

Angular acceleration = a/R

2.4525/0.3 = 8.175

8.175 rads/sec^-2

C,

T=mg-ma

T=0.5*9.81-0.5*2.4525

T=3.68

3.68N

D, -

**The problem!**

Torque (TNET) = acceleration torque (TA) + frictional torque (TF)

TF = TR

3.68*0.3

1.103625

TA = Angular acceleration*I

I = MpR^2/2

I = 3*0.3^2/2

I = 0.135

0.135*8.175

= 1.103625

Thus suggestion there is no frictional Torque,

I have spent a few weeks on an off with this question, I have looked at out threads on here, the lesson provided with the module and YOUTUBE. I am still not able to work out were I am going wrong, hope someone can help, Thanks,

Torque (TNET) = acceleration torque (TA) + frictional torque (TF)

TF = TR

3.68*0.3

1.103625

TA = Angular acceleration*I

I = MpR^2/2

I = 3*0.3^2/2

I = 0.135

0.135*8.175

= 1.103625

Thus suggestion there is no frictional Torque,

I have spent a few weeks on an off with this question, I have looked at out threads on here, the lesson provided with the module and YOUTUBE. I am still not able to work out were I am going wrong, hope someone can help, Thanks,