Chapter 11.6, Problem 2LC

To determine

What amount of weight should you put 6 ft from the fulcrum to balance the lever?

Answer to Problem 2LC

120-lb

Explanation of Solution

Given Information:

An 80-lb weight is placed on a lever, 9ft from the fulcurm.

Concept Used:

• Inverse variation is used.
• The weight of an object on a lever and its distance from the fulcrum are in inverse variation.
• The product of the weight of the object and its distance from the fulcrum is always constant.

Calculation:

Let x be the weight of object 6 ft from the fulcrum.

And an 80-lb weight is placed on a lever, 9ft from the fulcurm.

  $\begin{array}{c}weigh{t}_1\cdot dis\tan c{e}_1=weigh{t}_2\cdot dis\tan c{e}_2\\ So\left(80\right)\cdot 9=x\cdot 6\\ 720=6x\\ x=\frac{720}{6}\\ x=120\end{array}$

120-lb weight is placed to put 6 ft from the fulcrum to balance the lever.