A balanced lever has two weights on it, the first with mass 9 kg and the second with mass 32 kg. If the first weight is 6 m from the fulcrum, how far is the second weight from the fulcrum?

2 Answers
Feb 25, 2016

27/16 m.

Explanation:

For a balanced lever the torque on the two ends must be equal.

Torque can be defined as "mass" xx "distance from fulcrum"

So
color(white)("XXX")m_1xxd_1 = m_2 xx d_2

or for the given data:
color(white)("XXX")9 " kg"xx6" m" = 32" kg" xx d_2 " m"

color(white)("XXX")d_2=(9xx6)/32 " m" = 27/16" m"

Feb 25, 2016

Second weight is 54/32=1.6875 m far from fulcrum.

Explanation:

Let the the second weight be x m far from the fulcrum.

As the lever is balanced, moment (M=F*d, where F is force applied and d is its distance from fulcrum) of the two weights should be equal.

Moment of first weight is 9*6=54 and as it balances second weight of 32 kg, the latter's distance should be

54/32=1.6875 m.