Q:

The weight needed to balance a lever varies inversely with the distance from the fulcrum to the weight. A 120-lb weight is placed on a lever, 5 ft from the fulcrum. What amount of weight should be placed 8 foot from the fulcrum to be balanced.A). 120B). 75C). 8D). 125i think, not 100% sure, like 90% sure, it's B. 75.

Accepted Solution

A:
Let w represents the weight and d represents the distance.It is given thatThe weight needed to balance a lever varies inversely with the distance from the fulcrum to the weight. A 120-lb weight is placed on a lever, 5 ft from the fulcrum. [tex]w = \frac{k}{d}[/tex]Substituting the values of w and d, we will get[tex]120= \frac{k}{5} \\ k =600lb \ ft[/tex]Using the value of k which is 600, with the above equation and the given value of d which is 8, we will get[tex]w = \frac{600}{8} = 75lb[/tex]Therefore the correct option is B .