# Deflection of Beams - Rearrange formula

1. Oct 28, 2009

### MikeNZ

Deflection of Beams - Rearrange formula [URGENT]

1. The problem statement, all variables and given/known data

Deflection for a simply supported beam... I calculated the deflection of it to be 9.72mm downwards, but there is a support 6mm from the original position and need to calculate the force on the support...

The original formula for deflection is:

y = - (F x L^3)/(48 x E x I)

where 'x' is just the multiplication symbol.

2. Relevant equations

y = - (F x L^3)/(48 x E x I)

3. The attempt at a solution

To find the force on the support, I went 9.72-6 = 3.72mm

I substituted 3.72 into the equation above as 'y', now, how do i rearrange the formula to find F?

My attempt:

F = (48 x E x I)/(Y x L^3)

I get 2.212 MPa, this surely can't be right as the original load on top is 80KN. Did I rearrange correctly?
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Oct 28, 2009

### PhanthomJay

Re: Deflection of Beams - Rearrange formula [URGENT]

Is this a beam on 3 supports?

3. Oct 28, 2009

### MikeNZ

Re: Deflection of Beams - Rearrange formula [URGENT]

Simply supported, no, not 3 supports, doesn't matter I've figured it out now. Thanks.