Question

A balanced lever has two weights on it, the first with mass `7 kg` and the second with mass `55 kg`. If the first weight is `9 m` from the fulcrum, how far is the second weight from the fulcrum?

Answer 1

The distance is `=1.15m`

Explanation:

The mass `M_1=7kg`

The mass `M_2=55kg`

The distance `a=9m`

Taking moments about the fulcrum

`M_1xxa=M_2xxb`

The distance is

`b=(M_1xxa)/(M_2)=(7*9)/(55)=1.15m`

Answer 2

Approximately `1.15` meters from the fulcrum

Explanation:

On a balanced lever, we have the following relationship:

`m_1d_1=m_2d_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, we got:

`7 \ "kg"*9 \ "m"=55 \ "kg"*d_2`

`d_2=(7color(red)cancelcolor(black)"kg"*9 \ "m")/(55color(red)cancelcolor(black)"kg")`

`~~1.15 \ "m"`