For a disc with mass m, radius R, and moment of inertia about center of mass of (mR^2)/3, and applied external force is F.(adsbygoogle = window.adsbygoogle || []).push({});

A wheel is being pulled by a force F directly upwards, which causes it to roll without slipping (due to static friction), on a horizontal surface. The upward force F is applied at the most right tip or edge of the disc.

Find theacceleration, a, and thestatic frictional force, f.

I'm not sure how to set up the torque or force equations etc....

So, if F is directly upward, and on the edge, is it like F*cos90=0, so

0-f=ma?

and second equation,

F*(2R)=(moment of inertia about point of contact of disc and surface) * (angular speed)

where

moment of inertia about point of contact = (moment of inertia about center of mass, given) + m*R^2

and

angular speed=a/R (because no slip?)

so in this case, solving the F*2R= --- etc. equation, we get

a=3F/2m

and using 0-f=ma,

f=-3F/2

Does this sound right at all or what should I do? Any suggestion is much appreciated!!!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Torque and acceleration Please help!

**Physics Forums | Science Articles, Homework Help, Discussion**