Posted by Jake on Wednesday, April 18, 2012 at 10:15am.
Two masses, m1=3kg and m2=2kg, are suspended with a massless rope over a pulley of mass M = 10kg. The pulley turns without friction and may be modeled as a uniform disk of radius R=.1m. You may neglect the size of the masses. The rope does not slip on the pulley. The system begins at rest.
If m1 starts at a height h=1m above the ground, what is its speed v when it hits the ground?
I've tried a few different ways to get it but I can't seem to get the answer. I've tried using the sum of the torques as well as trying to use energy. I can't seem to figure it out, any help is much appreciated!

Physics  Elena, Wednesday, April 18, 2012 at 5:47pm
In vector form
m1•¬a = m1•¬g  ¬T1
m2•¬a = m2•¬g  ¬T2
I•¬ε =¬M
Projections on the vertical axis:
m1•a = m1•g  T1,
m2•a = m2•g – T2,
(mR^2/2)•(a/R) = (T1T2)•R.
Solving this system for acceleration a, we obtain
a= (m1m2)•g/(m1 +m2+m/2) =(32)/(3+2+10/2) = 0.1 m/s^2.
Since
s =v^2/2•a.
v =sqrt(2•a•s) = sqrt(2•0.1•1)= 0.45 m/s.

Physics  Jose, Wednesday, December 16, 2015 at 3:54pm
The acceleration should come out as 0.1g actually.
So, v = sqrt(2*a*s) = sqrt(2*0.1g*1) = 1.40m/s

Physics  fook you m8, Wednesday, April 20, 2016 at 3:21pm
get outta here uiuc boii
Answer This Question
Related Questions
 physics  Consider the system shown in the diagram. The pulley is a uniform ...
 physics  Two masses are suspended from a pulley as shown in the figure below (...
 physics  Two masses are suspended from a pulley as shown in the figure below (...
 physics  Two masses are suspended from a pulley as shown in the figure below (...
 Physics  Two masses are suspended from a pulley as shown in the figure . The ...
 Physics  Two masses are suspended from a pulley as shown in the figure . The ...
 physics  Two blocks are connected by a massless rope that passes over a pulley...
 Physics  Suppose you have a system of two masses strung over a pulley. Mass 1 (...
 Physics  In the figure, the two blocks are attached by a massless rope over a ...
 physic 2210  A pulley (a soild disk) with mass 2kg and radius 0.3 m is attached...
More Related Questions