# A balanced lever has two weights on it, one with mass 3 kg and one with mass 8 kg. If the first weight is  7 m from the fulcrum, how far is the second weight from the fulcrum?

Aug 27, 2016

$\frac{21}{8}$ The force times distance on one side must balance the force times distance on the other side.

#### Explanation:

${M}_{1} \times {D}_{1} = {M}_{2} \times {D}_{2}$

The force x distance on one side of the fulcrum must equal the force times the distance on the other side of the fulcrum.

${M}_{1}$ = 3 kg

${D}_{1}$ = 7 m

${M}_{2}$ = 8kg

${D}_{2}$ = an unkown.

Subsitute the values into the equation and solve.

$3 \times 7 = 8 \times {D}_{2}$

$\frac{21}{8} = {D}_{2}$

$2 \frac{5}{8} = {D}_{2}$