How can you explain how a balance works vectorially?

In summary, a balance with 1kg weight in each 1 meter long arm will be balanced when horizontal and will not move when a 10 N force is applied to each 1 meter long arm. However, when the balance is leaned at a 45 degree angle, the vertical force will be cos 45 * 10 N in each arm, resulting in the balance staying in that position due to equal forces. This may contradict basic physics, but it has been tested in a non-ideal experiment where the force from the central support is no longer symmetrical when the balance is tilted. Vectors also fail to explain how a balance works, as it may tend to level horizontally even when there are unequal weights in each arm.
  • #1
eosphorus
78
0
you have a balance with 1kg weight in each 1 meter long arm

when its horizontal each 10 N force * 1 m long will balance so the balance won't move

but when you lean the balance 45º the vertical force will be cos 45 * 10 N in each arm so the balance should stay in that position since the forces are equal but it tend to level horizontal

can anyone explain this please
 
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  • #2
All I can do is ask where you got the idea that a balance in such a situation would tend to leve!
 
  • #3
its not only what basics physics say but besides i have tested it myself in case that basic physics were wrong
 
  • #4
I am betting it has to do with the force between the ballance and the central support. I am guessing, that in your (non-ideal) experiment the force from the support is no longer symmetrical once the balance is tilted.
 
  • #5
im afraid i disagree basic physics says a balance will balance or level with equal weights in its arms

the problem is that you can't prove it vectorially what doesn't mean the balance won't level simply vectors fail to explain a simple physical process
 
  • #6
besides if you put 1kg in one arm and 2 kg in the other arm and aply vectors the balance will tend to put vertical according to vectors but balances don't behave that way

i insist vectors fail to explain how a balance works
 

1. How does a balance measure weight?

A balance measures weight by comparing the weight of an object placed on one side of the balance to a known weight on the other side. The balance will tilt towards the heavier side, and the weight is determined by adding or removing weights on the known side until the balance is level.

2. What is the purpose of the pivot point in a balance?

The pivot point, or fulcrum, is the point where the balance arm is able to rotate freely. It allows the balance to accurately measure weight by distributing the weight of the object evenly between the two sides.

3. How does a balance account for the direction of force?

A balance works vectorially by using a lever arm and pivot point to determine the direction of force applied to an object. The balance arm will tilt in the direction of the force, and the weight is calculated based on the distance of the object from the pivot point.

4. What is the difference between a balance and a scale?

A balance measures weight by comparing two masses, while a scale measures weight by using a spring or other mechanism to determine the force of gravity on an object. Balances are typically more precise and accurate than scales, but scales are easier to use and more portable.

5. How can a balance be used to calculate unknown weights?

A balance can be used to calculate unknown weights by using a known weight and the concept of equal torques. The unknown weight can be determined by setting up a balance equation and solving for the unknown weight using the known weight and distance of the object from the pivot point.

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