SOLUTION: A 10 foot long balance bar (of negligible weight)as a 50 pound weight applied at the left end and a 75 pound weight applied on the right end. How far is the fulcrum point located

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Question 1147886: A 10 foot long balance bar (of negligible weight)as a 50 pound weight applied at the left end and a 75 pound weight applied on the right end. How far is the fulcrum point located from the right end?
Found 2 solutions by greenestamps, ikleyn:
Answer by greenestamps(13209) About Me  (Show Source):
You can put this solution on YOUR website!


Let x be the distance of the fulcrum from the right end. Then the distance from the fulcrum to the left end is 10-x.

The products of the distances and weights must be equal:
75%28x%29+=+50%2810-x%29
75x+=+500-50x
125x+=+500
x+=+4

ANSWER: The fulcrum is 4 feet from the right end.

or...

The ratio of the weights is 50:75 or 2:3, so the ratio of distances from the fulcrum must be in the ratio 3:2.

So the distance of the fulcrum from the 75-pound weight is 2x and the distance from the 50-pound weight is 3x. Then

2x%2B3x+=+10
5x+=+10
x+=+2

The distance of the fulcrum from the 75-pound weight is 2x = 4 feet.

For a student learning how to solve problems using algebra, the first solution method is probably better practice.

But if getting the answer quickly is what is important, I find the latter solution method easier and faster.

Answer by ikleyn(52890) About Me  (Show Source):
You can put this solution on YOUR website!
.

Let me show you how your post should be re-formulated to make sense.

On the way, learn an appropriate terminology. 

    A 10 foot long balance bar (of negligible weight) highlight%28cross%28as%29%29 is in equilibrium having a 50 pound weight applied at the left end 
    and a 75 pound weight applied on the right end.  How far is the fulcrum point located from the right end?


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