
Amy M. answered 03/14/15
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CalTech Grad, Software engineer with 30+ years experience.
Given that Q=W/(1-(T0/T)) and Q=a(T-T0)
W/(1-(T0/T)) = a(T-T0)
W=(1-(T0/T))• a(T-T0)
WT = a(T-T0)^2
W/(1-(T0/T)) = a(T-T0)
W=(1-(T0/T))• a(T-T0)
WT = a(T-T0)^2
0=aT^2-(a2T0+W)T+aT0^2
Using quadratic formula
T=T0+W/(2a)+-sqrt((a2T0+W)^2-(2aT0)^2)/2a
T=T0+W/(2a)+-sqrt((T0+W/2a)^2-(T0)^2)
T=T0+W/(2a)+-sqrt((T0W/a+(W/2a)^2)
T=T0+W/(2a)+-W/2a•sqrt((4aT0/W+1)
T=T0+W/(2a)(1+-sqrt((4aT0/W+1)
I suspect the real world causes the discard if the - solution. But I don't know?
This differs from the answer given by a plus sign.
Michael J.
03/14/15