- #1
dagg3r
- 67
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Hi guys, i am trying to work out the uncertainty of this equation
Y = (AC-CX)/(B+X)
and i am needed to work out the uncertainty in Y.
values for these are:
Y=2.18 UNCERTAINTY UNKNOWN
A=29m Uncertainty in A denoted (Sa)=3mm
B=710mm Uncertainty in B denoted(Sb)=3mm
C=5.85mm Uncertainty in C denoted(Sc)=0.2mm
D=0.150mm Uncertainty in D denoted (Sd)=0.005mm
X=18.68m Uncertainty in X denoted (Sx)=0.005mm
using these values i used the formula:
Sy/Y = (Sc/C)+ S[(A-x)(B+x)]/[(A-x)(B+x)]
Sy/Y = (0.2/5.85) + (0.1099555934/0.3723445134)
Sy= 0.7182971382
i obtained an uncertainty of 0.7 it is very large hence i think i may have done something wrong in my calculations.
to obtain S[(A-x)(B+x)]
i did
[S(A-x)/(a-x)] + [S(B+x)/(B+x)]
=[(3mm+.005)/(29-18.68)] + [(3mm+.005)/(710+18.68)]
=0.1099555934
so can anyone please check this thanks!
also another simple question
Y= (AC-CX)/(B+X)
how do i derive for B, keeping everything else constant?
eg if i were to derive with respect to C, whilst keeping everything else constant i would get
: [A-X/(B+X)] ... so how do i derive with respect to B while keeping everything else constant since it is in the denomitor...
THANKS ALL
Y = (AC-CX)/(B+X)
and i am needed to work out the uncertainty in Y.
values for these are:
Y=2.18 UNCERTAINTY UNKNOWN
A=29m Uncertainty in A denoted (Sa)=3mm
B=710mm Uncertainty in B denoted(Sb)=3mm
C=5.85mm Uncertainty in C denoted(Sc)=0.2mm
D=0.150mm Uncertainty in D denoted (Sd)=0.005mm
X=18.68m Uncertainty in X denoted (Sx)=0.005mm
using these values i used the formula:
Sy/Y = (Sc/C)+ S[(A-x)(B+x)]/[(A-x)(B+x)]
Sy/Y = (0.2/5.85) + (0.1099555934/0.3723445134)
Sy= 0.7182971382
i obtained an uncertainty of 0.7 it is very large hence i think i may have done something wrong in my calculations.
to obtain S[(A-x)(B+x)]
i did
[S(A-x)/(a-x)] + [S(B+x)/(B+x)]
=[(3mm+.005)/(29-18.68)] + [(3mm+.005)/(710+18.68)]
=0.1099555934
so can anyone please check this thanks!
also another simple question
Y= (AC-CX)/(B+X)
how do i derive for B, keeping everything else constant?
eg if i were to derive with respect to C, whilst keeping everything else constant i would get
: [A-X/(B+X)] ... so how do i derive with respect to B while keeping everything else constant since it is in the denomitor...
THANKS ALL