# Deflection calculation

Morning,
I am running a deflection calculation to size the amount of force needed to pre-bow a piece of rectanglur steel 2mm. I have run the
calculation two ways and am getting different results. Can someone point me to where my error is? Thanks in advance
Here is one run
Y= P(L^3) -------- 3EI
Pu00 lbs L(length of moment arm) = 4.8inches E(Modulus of elasticity) = 205 Gpa = 29732737 psi I(Moment of inertia) = .781 in^4
Deflection = 7500 * ((4.8)^3) -------------- 3 * (29732737) * (.781in^4)
Y = 829,440 ------- 69663802
Y = .011 in = .254 millimeter
Here is the other run
Pu00lbs = 3401 kg L = 4.8 in = 12.192 cm E = 205 Gpa = 2090418 kg force/cm^2 I = .781 in^4 = 1.9 cm^4
Y = (3401)*((12.192)^3) ------------------------- 3 (2090418) (1.9)
Y = 6163558 ----------- 11915382.6
Y = .51cm
Y = 5.1mm
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
There's a big error in your moment of inertia units conversion. There are 41.63 (cm/in)^4
Dave
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>