Question

The force needed to break a board varies inversely with its length. If Tom uses 20 lb of pressure to break a 1.5-ft board, how many po

essure would he need to use to break a 6 -board?​

Answer 1

If the force F and the length L are inversely proportional, then their product is constant:

`FL=k`

Given the values F=20 and L=1.5, we can deduce that the constant is

`20\cdot 1.5=30`

So, given L=6, we can solve for F as follows:

`6F=30 \iff F=5`