# A balanced lever has two weights on it, the first with mass 34 kg  and the second with mass 68 kg. If the first weight is  3 m from the fulcrum, how far is the second weight from the fulcrum?

May 16, 2017

The second weight $68 k g$ is $1.5 m$ from the fulcrum.

#### Explanation:

The balanced lever is a simple scale in this configuration.
If the two weights balance each other then the distance from the fulcrum to each must be in proportion to the two weights.

That is: ${w}_{1} \cdot {d}_{1} = {w}_{2.} {d}_{2}$

We were told that:

w_1=34kg; w_2=68kg; d_1=3m

So: $34 k g \cdot 3 m = 68 k g \cdot {d}_{2}$

$\cancel{34 k g} \cdot 3 m = \cancel{68 k g} \cdot {d}_{2}$

$2 {d}_{2} = 3 m$

${d}_{2} = 1.5 m$