# Finding weight of a mass

1. May 14, 2013

### patehi

Hey guys, i need you help to find the weightof a mass required to produce the same applied force to rods.
(sorry english is not my first language) i will try to explain this with a diagram.

1. The problem statement, all variables and given/known data
First problem:
So lets say i have 10 small rods with a diameter of 2mm and a length of 3cm.
they are positioned next to each other, and stand on the ground. Then i have a weight that is applying force to those 10 rods alltogether. SO my question is, how much is the weight of the mass that i need, to make sure that every rods will be applied 50g(0,49N) each.

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known values:
F(on each rods)= 0.49N or 50g
length of each rod=3cm
diameter or a rod=2mm

Problem 2:
Now its exactly the same as situation 1, but the rods are positioned at a distance from each other, lets say this distance is x=2mm
How much is the weight required for applying each rods the same force of 0.49N?

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2. Relevant equations
g=9,81ms-2
1000g=1kg=9,81N

3. The attempt at a solution

Problem 1
For applying each rod 0.49N,
the mass should be= 10rodsx0.49N= 4,9N which is about 500g
i wish it would be that easy, but i think theres got to be something that is not right?

Problem 2
this is actually very confusing, so i cant really know how to go with it, would you guys help me?

Thanks!!

Last edited by a moderator: May 6, 2017
2. May 14, 2013

### barryj

Seems like problem 1 is correct. Why would spacing the rods make a difference?