Physics balancing problem?
It says "A 2kg mass is 5m away from the fulcrum of a see-saw. Where must a 3kg mass be placed to balance the see-saw?
can you guys explain how you did it please?
- 9 years agoBest Answer
lets balance the see-saw. So it'll rotate neither left nor right, right?
That's, in examination jargon, moments about the fulcrum add to zero
But what weighs 2 Kg and is found 5m from a seesaw fulcrum? A large seesaw too , if u ask me ;-)
- biire2uLv 79 years ago
To balance, you have to have the fulcrum point be the "equal sign" in your equation, so that you have the (mass1 x distance1 from fulcrum) = (second mass2 x distance2 from fulcrum)
2kg * 5m = 3 kg * X
solve for X:
X = 2kg* 5m / 3kg
X = 3.33m
So this means if the 2kg is 5m from the pivot point, then the 3kg on the other seat of the see saw will be 3.33m from the pivot
- 9 years ago
there must be a balance of torque. torque = force * distance. so on one side there is a 2kg mass 5m away. 2kg * 5m is 10 and that is the torque on that side. now on the other side u need the same torque. therefore u need 10= 3kg* d where d is the distance. you solve it and divide 10/3 to get 3 and a third. not 3.5 lol
- TBTLv 79 years ago
weight of 2kg = 2g N
weight of 3kg = 3g N
moment of 2g N about fulcrum = moment of 3g N about fulcrum
2g * 5 = 3g * x
x = 10/3 = 3.333 m ---answerSource(s): my brain (Prof TBT)
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- 9 years ago