A balanced lever has two weights on it, the first with mass 22 kg  and the second with mass 21 kg. If the first weight is  4 m from the fulcrum, how far is the second weight from the fulcrum?

Apr 15, 2018

$4.2 \setminus \text{m}$

Explanation:

For a balanced lever, we have the following relationship:

${m}_{1} {d}_{1} = {m}_{2} {d}_{2}$

• ${m}_{1} , {m}_{2}$ are the masses of the two objects

• ${d}_{1} , {d}_{2}$ are the distances of the two objects from the fulcrum

And so,

$22 \setminus \text{kg"*4 \ "m"=21 \ "kg} \cdot {d}_{2}$

${d}_{2} = \left(22 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{kg"*4 \ "m")/(21color(red)cancelcolor(black)"kg}}}}\right)$

$\approx 4.2 \setminus \text{m}$