Torque

Any net torque on an object will cause a change in its rotational state. Torque (t) is found by:

t = Force x lever arm

t = (F)(r)

and, in terms of rotational quantities (for which you are now an expert, having read the rotational section),

t = Ia

where I = the moment of inertia (usually given or calculated by I = mr²)

and a = angular acceleration

Let's do an example:

A bucket on a well...

t = Fr

t = (mg)r

t = (4.3)(9.8)(0.15)

t = _____ (N)(m)

Now, to find the angular acceleration, you can use

t = Ia

("I" is given in the picture above)

etc.