- #1
madah12
- 326
- 1
Homework Statement
http://img148.imageshack.us/img148/8686/ssslk.png
the two boxes and the pulley have the same mass
I=.5mr^2
the system is accelerating downwards calculate the magnitude of the acceleration
Homework Equations
The Attempt at a Solution
I will call the falling one D and the higher one U
mg-Td=ma
Td=mg-ma
Tu=ma
by torque
Td-Tu=I alpha/r
Td-Tu=I a/r^2
Td-Tu=(.5mr^2) a/r^2
Td-Tu==.5ma
mg-ma-ma=.5ma
2.5a=g
a=g/2.5=3.5
what's wrong here??
in the exam I got 4 out of 5 in this question I can't see why I didnt get a full mark I revised everything
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