Posted by Goldberg on Saturday, May 5, 2012 at 9:07pm.
One end of the string in the diagram at right is wrapped around the cylinder. The other end is tied to the ceiling. The cylinder is released from rest. How fast is it moving after it falls 3.0m?

Physics 121  Goldberg, Saturday, May 5, 2012 at 9:08pm
Please show the formula and how you do it. Thx

Physics 121  bobpursley, Saturday, May 5, 2012 at 9:13pm
Look at energy:
potential energy lost= kinetic energy gained
mgh=1/2 m vf^2 +1/2 I w^2
mgh=1/2 m vf^2 + 1/2 I (vf/r)^2
Now, you have to decide the moment of inertia for the cylinder. Solid, or not. Lets just assume it is hollow for this demonstration.
I= m r^2
then
mgh= 1/2 m vf^2+1/2 m vf^2
Now, average velocity going down was Vf/2, so in three seconds it went 1.5Vf
h= 1.5Vf
1.5 mg Vf= 1/2 m Vf^2+ 1/2 m Vf^2
you can solve for Vf.
I would divide by mVf, and solve
Answer This Question
Related Questions
 Physics  A massless string is wrapped around a cylinder of mass 0.400 kg and ...
 Physics  Consider a stainless steel annular disk with an outer radius 68mm and ...
 Physics  Consider a stainless steel annular disk with an outer radius 68mm and ...
 Physics  Consider a stainless steel annular disk with an outer radius 66 mm and...
 PHYSICS  A bucket containing cement has a mass of 3kg. One end of a rope is ...
 physics incline  A cord connected at one end to a block which can slide on an ...
 physcs  A string is wrapped around a uniform solid cylinder of radius 3.10 cm, ...
 Physics C: Mechanics  A 1.00 kg mass is attached to a string wrapped around a ...
 physics  A string is wrapped around a uniform solid cylinder of radius r. The ...
 Physics College  Experiment in this week (week 8) is to study rotational ...
More Related Questions