Here is the problem: A uniform meter sticksupported at the 25-cm mark is in equi
ID: 1663269 • Letter: H
Question
Here is the problem: A uniform meter sticksupported at the 25-cm mark is in equilibrium when a 1=kg rock issuspended at the 0-cm end. Is the mass of the meter stick greaterthan equal to, or less than the mass of the rock? Explain yourreasoning.My thinking: I figured that because the moment arm of the rock wasless than the moment arm of the meter stick, that the rock wouldweigh more but apparently it is equal to. I'm just having a hardtime comprehending why it is equal to and not the rock greater thanthe meter stick. Any help is much appreciated, thank you.
Explanation / Answer
Mass of rock is 'm' and of stick is 'M' .Now by momentum balance,
mx 1/4 + (M / 4) x 1/8 = (3M / 4) x 3/8
By taking the center of mass of both of the sides of thestick at mid point of them. So, the COM of 3/4th part will lie at distance of 3/8th lengthof the stick measured from the center of fulcrum.Same for the otherside.
so yes, it will show that m = M