# concept guidance

1. Jan 23, 2008

### physixguru

how to solve pulley related rotational mechanics problems....

the ques are of the kind...

mass is attached to a pulley which is further attched to larger pulley...

and the moment of inertia of both along wid their radius is given...

mass of the load is given...

asks to calculate tension between the wire joining the two pulleys...

what should be the intial cocept...

2. Jan 23, 2008

### andrevdh

Have you tried

loss in PE of load = gain of KE of pulleys, load and trolley ?

Last edited: Jan 23, 2008
3. Jan 23, 2008

### physixguru

Thanks Bro..shall Do It...

4. Jan 24, 2008

### andrevdh

Note that the acceleration of the system (out of rest) when the load has dropped through a distance h is given by:

$$v^2 = 2ah$$

$$a = \frac{v^2}{2h}$$

5. Jan 25, 2008

### physixguru

hey thanks a million times frnz but that guidance is not enough for me to solve these kind of problems..

A string is wrapped around a wheel of moment of inertia=.20 kgm^2 and radius = 10 cm.
It goes through a light pulley of radius 5 cm and M.I=.10 kg m^2, to support a mass of 2kg.
Find the tension in the part of string joining the pulleys and and the acceleration of the block...

REALLY HAVING TROUBLE CALCULATING NET TORQUE AND CONSTRAINT RELATIONS..

PLS GUIDE ME THROUGH FRNZ..

IMAGE ATTACHED..

Last edited: Feb 29, 2008