Problem $4$:

Inputs:

$a=4\mathrm{.}5"($the "symbol indicates inches$)$

$b=\frac{1}{4^{n\text{'}}}($rod diameter$)$

$F_1=13lb$

Have you ever wondered how bolts get their threads? Well, we start with a smooth rod and then cut the threads into it$.$ The thing that cuts the threads is called a "die." Although machines can be used for this process, it is often done by hand as well, and that's what we're looking at on the right.

So suppose you want to cut threads on this rod. You would get the correct size die $($they come in lots of different sizes$),$ and place it inside the handle. Then you would twist the handles around the rod, thereby cutting the threads with each revolution.

For this problem, suppose you apply a force of $F_1$ to the handles. What is the force $F_2$ exerted on the rod? Use couples for your solution.