If you are given many closed sacks filled with different amounts of identical marbles, how could you determine the weight of a single marble without opening the sacks? (Assume the weight of the sack material can be ignored.)
2007-03-01 01:37:46 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
I wonder if you can dunk these sacks in water?(just kidding)
Ok.
Write equations like
m(N1-N2)=M1-M2 (you can write at least 3 equations like this one for a 3 sack 'system'.)
where m mass of a single marble
N1- Number of marbles in sack #1
M1 - Mass i sack #1
Sice mN1/mN2= M1/M2
The replace N1 = N2 M1/M2
This will reduce the number of unknowns.
One of the equations you will end up with will be
m(N3(M2/M3)(M1/M2) - N3(M2/M3))=M1-M2
the other one
m(N3(M2/M3)(M1/M2) - N3)=M1-M3
you have 2 equations and 2 unknowns.
Does that help?
2007-03-01 02:29:02 · answer #1 · answered by Edward 7 · 0⤊ 0⤋
Measure each sack's mass and divide by the approximate number of marbles in there. Do this for each sack and take an average of the values. Then multiply by 9.81 to find the weight
2007-03-01 09:53:45 · answer #2 · answered by SS4 7 · 1⤊ 0⤋