Friday

July 25, 2014

July 25, 2014

Posted by **Goldberg** on Saturday, May 5, 2012 at 9:07pm.

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

- Physics 121 -
**bobpursley**, Saturday, May 5, 2012 at 9:13pmLook 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

**Related Questions**

Physics - A massless string is wrapped around a cylinder of mass 0.400 kg and ...

physcs - A string is wrapped around a uniform solid cylinder of radius 3.10 cm, ...

physics - A string is wrapped around a uniform solid cylinder of radius r. The ...

Physics - Consider a stainless steel annular disk with an outer radius 66 mm 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 incline - A cord connected at one end to a block which can slide on an ...

physics - A long string is wrapped around a 6.2cm diameter cylinder, initially ...

physics - A light inflexible cable is wrapped around a cylinder of mass , radius...

Physics College - Experiment in this week (week 8) is to study rotational ...