An axle has two wheels of radii 0.95m and 0.15m attached to it. A 30 N force is applied horizontally to the edge of the larger wheel and a similar weight hangs from the edge of the smaller wheel. Draw a diagram and determine:
a) The net torque acting on the axle.
b) The maximum weight that the 30 N force can pull up.

Question

An axle has two wheels of radii 0.95m and 0.15m attached to it. A 30 N force is applied horizontally to the edge of the larger wheel and a similar weight hangs from the edge of the smaller wheel. Draw a diagram and determine:
a) The net torque acting on the axle.
b) The maximum weight that the 30 N force can pull up.

anonymous · Answer

|dw:1363471759251:dw|
$$\tau=\Sigma F\cdot d$$

anonymous · Answer

thanks again! :) so it's force and work?

anonymous · Answer

why work?

anonymous · Answer

isn't that what you have to find?

anonymous · Answer

says torque.. $$\vec{\tau}=\vec{r}\times\vec{F}$$
it is the cross-product

anonymous · Answer

which r is which exactly? the force is the 30 N and the r is the radius?

anonymous · Answer

yep. but I think, the force F and w are on opposite sides. otherwise, the question does not make sense

anonymous · Answer

yeah I guess you got a point. so what's w?

anonymous · Answer

w=F in magnitude.
but,|dw:1363472726242:dw|