A balanced lever has two weights on it, the first with mass 7 kg and the second with mass 4 kg. If the first weight is 3 m from the fulcrum, how far is the second weight from the fulcrum?

1 Answer
Feb 3, 2016

Weight 2 is 5.25m from the fulcrum

Explanation:

Moment = Force * Distance

A) Weight 1 has a moment of 21 (7kg xx3m )

Weight 2 must also have a moment of 21

B) 21/4 = 5.25m

Strictly speaking the kg should be converted to Newtons in both A and B because Moments are measured in Newton Metres but the gravitational constants will cancel out in B so they were left out for simplicity's sake