Find the placement for 4th mass

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To balance the meter stick with four identical masses, the equation m1r1 + m2r2 + m3r3 + m4r4 must be satisfied, where the distances r1, r2, and r3 are given as 25 cm, 45 cm, and 90 cm respectively. The fourth mass's position needs to be determined to ensure the total torque around the fulcrum is equal on both sides. Since the masses are identical, they can be treated as an unknown variable, allowing for simplification in calculations. The discussion raises questions about potential typos in the problem statement and clarifies the need to identify the correct values for the distances in the torque equation. The solution involves calculating the position of the fourth mass to achieve balance.
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Homework Statement


a meter stick is initially balanced on a fulcrum at its midpoint. you have four identical masses. three of them are placed at the following locations: 25 cm, 45 cm, and 90 cm. where should the fourth mass be placed in order to balance the meter stick?

Homework Equations


T=rxF ; m1r1+m2r2=m3r3=m4r4
each mass is identical but the problem does not give a mass.

The Attempt at a Solution

 
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leighkla said:
each mass is identical but the problem does not give a mass.
Don't let that stop you. Just fill in the masses as an unknown m and trust that if there is no mistake in the question then m will disappear later.
leighkla said:
m1r1+m2r2=m3r3=m4r4
Is there a typo in there?
What values for r1, etc. should you plug in?
 
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