Two boys each of mass 10kg sit at a distance 1.5metres from a pivot of a seasaw. If another boy of mass 30kg sit at the distance 1.0metres from the pivot, would the seasaw balance horizontally?
30(1)=2*10*1.5 ???
30=30
yes.
No, because the seesaw was already balanced. So, when the 3rd boy climbed on, it became unbalanced.
Balanced: F1*d1 = F2*d2.
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I assumed the 2 boys were on opposite sides of the pivot; because if they were on the same side, they occupied the same space at the same time which is impossible.
To determine if the seesaw will balance horizontally, we need to calculate the moments (or torques) on both sides of the pivot.
The moment of an object is the product of its mass and its distance from the pivot point. It is a measure of how much a force causes an object to rotate. In this case, we can consider the weight of the boys as the force causing the rotation.
Let's calculate the moments on each side of the pivot.
For the two boys with a mass of 10kg each, sitting at a distance of 1.5 meters from the pivot:
Moment on the left side = Mass * Distance = 10kg * 1.5m = 15kg•m
Moment on the right side = Mass * Distance = 10kg * 1.5m = 15kg•m
Since both boys are equidistant from the pivot, their moments have the same magnitude but opposite direction. Therefore, their moments cancel each other out.
Now, let's calculate the moment of the third boy with a mass of 30kg sitting at a distance of 1.0 meter from the pivot:
Moment on the right side = Mass * Distance = 30kg * 1.0m = 30kg•m
Since the moment on the right side (30kg•m) is greater than the combined moments on the left side (15kg•m each), the seesaw will not balance horizontally. The heavier boy at a shorter distance from the pivot is exerting a larger moment and causing an imbalance.
In summary, the seesaw will not balance horizontally due to the unequal moments created by the different masses and distances from the pivot.