A balanced lever has two weights on it, the first with mass $3 k g$ $3 kg$ and the second with mass $4 k g$ $4 kg$ . If the first weight is $25 m$ $25 m$ from the fulcrum, how far is the second weight from the fulcrum?

Question

1382 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-08-13T15:26:19

$l_{2} = 18.75 m$ $l_2=18.75 " m"$

$Torque for the first weight:$ $"Torque for the first weight:"$

$L_{1} = m \cdot g \cdot l_{1}$ $L_1=m*g*l_1$

$m_{1} = 3 kg; g = 9.81 \frac{N}{k g}; l_{1} = 25 m$ $m_1=3" kg";g=9.81 N/(kg);l_1=25 "m"$

$L_{1} = 3 \cdot g \cdot 25 = 75 \cdot g N \cdot m$ $L_1=3*g*25=75*g" " N*m$

$Torque for the second weight:$ $"Torque for the second weight:"$

$L_{2} = m_{2} \cdot g \cdot l_{2}$ $L_2=m_2*g*l_2$

$m_{2} = 4 kg; l_{2} = ?$ $m_2=4" kg" " ; "l_2=?$

$L_{2} = 4 \cdot g \cdot l_{2}$ $L_2=4*g*l_2$

$L_{1} = L_{2} so the system is balanced$ $L_1=L_2 " so the system is balanced"$

$75*cancel(g)=4*cancel(g)*l_2$

$l_2=75/4$

$l_2=18.75 " m"$

A balanced lever has two weights on it, the first with mass 3 kg 3kg3 kg and the second with mass 4 kg4kg4 kg. If the first weight is 25 m25m 25 m from the fulcrum, how far is the second weight from the fulcrum?