
The 150-mm-thick wall of a gas-fired furnace is constructed of fireclay brick
(a) How long does it take for the outer surface of the wall to reach a temperature of 750°C’?
(b) Plot the temperature distribution in the va1l at the foregoing lime, as well as at several intermediate times.

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Chapter 3 Solutions
Introduction to Heat Transfer
- find the laplace transform for the flowing function 2(1-e) Ans. F(s)=- S 12) k 0 Ans. F(s)= k s(1+e) 0 a 2a 3a 4a 13) 2+ Ans. F(s)= 1 s(1+e") 3 14) f(t)=1, 0arrow_forwardFind the solution of the following Differential Equations Using Laplace Transforms 1) 4y+2y=0. y(0)=2. y'(0)=0. 2) y+w²y=0, (0)=A, y'(0)=B. 3) +2y-8y 0. y(0)=1. y'(0)-8. 4)-2-3y=0, y(0)=1. y'(0)=7. 5) y-ky'=0, y(0)=2, y'(0)=k. 6) y+ky'-2k²y=0, y(0)=2, y'(0) = 2k. 7) '+4y=0, y(0)=2.8 8) y+y=17 sin(21), y(0)=-1. 9) y-y-6y=0, y(0)=6, y'(0)=13. 10) y=0. y(0)=4, y' (0)=0. 11) -4y+4y-0, y(0)=2.1. y'(0)=3.9 12) y+2y'+2y=0, y(0)=1, y'(0)=-3. 13) +7y+12y=21e". y(0)=3.5. y'(0)=-10. 14) "+9y=10e". y(0)=0, y'(0)=0. 15) +3y+2.25y=91' +64. y(0)=1. y'(0) = 31.5 16) -6y+5y-29 cos(2t). y(0)=3.2, y'(0)=6.2 17) y+2y+2y=0, y(0)=0. y'(0)=1. 18) y+2y+17y=0, y(0)=0. y'(0)=12. 19) y"-4y+5y=0, y(0)=1, y'(0)=2. 20) 9y-6y+y=0, (0)-3, y'(0)=1. 21) -2y+10y=0, y(0)=3, y'(0)=3. 22) 4y-4y+37y=0, y(0)=3. y'(0)=1.5 23) 4y-8y+5y=0, y(0)=0, y'(0)=1. 24) ++1.25y-0, y(0)=1, y'(0)=-0.5 25) y 2 cos(r). y(0)=2. y'(0) = 0. 26) -4y+3y-0, y(0)=3, y(0) 7. 27) y+2y+y=e y(0)=0. y'(0)=0. 28) y+2y-3y=10sinh(27), y(0)=0. y'(0)=4. 29)…arrow_forwardAuto Controls A union feedback control system has the following open loop transfer function where k>0 is a variable proportional gain i. for K = 1 , derive the exact magnitude and phase expressions of G(jw). ii) for K = 1 , identify the gaincross-over frequency (Wgc) [where IG(jo))| 1] and phase cross-overfrequency [where <G(jw) = - 180]. You can use MATLAB command "margin" to obtain there quantities. iii) Calculate gain margin (in dB) and phase margin (in degrees) ·State whether the closed-loop is stable for K = 1 and briefly justify your answer based on the margin . (Gain marginPhase margin) iv. what happens to the gain margin and Phase margin when you increase the value of K?you You can use for loop in MATLAB to check that.Helpful matlab commands : if, bode, margin, rlocus NO COPIED SOLUTIONSarrow_forwardThe 120 kg wheel has a radius of gyration of 0.7 m. A force P with a magnitude of 50 N is applied at the edge of the wheel as seen in the diagram. The coefficient of static friction is 0.3, and the coefficient of kinetic friction is 0.25. Find the acceleration and angular acceleration of the wheel.arrow_forwardAuto Controls Using MATLAB , find the magnitude and phase plot of the compensators NO COPIED SOLUTIONSarrow_forward4-81 The corner shown in Figure P4-81 is initially uniform at 300°C and then suddenly exposed to a convection environment at 50°C with h 60 W/m². °C. Assume the = 2 solid has the properties of fireclay brick. Examine nodes 1, 2, 3, 4, and 5 and deter- mine the maximum time increment which may be used for a transient numerical calculation. Figure P4-81 1 2 3 4 1 cm 5 6 1 cm 2 cm h, T + 2 cmarrow_forwardAuto Controls A union feedback control system has the following open loop transfer function where k>0 is a variable proportional gain i. for K = 1 , derive the exact magnitude and phase expressions of G(jw). ii) for K = 1 , identify the gaincross-over frequency (Wgc) [where IG(jo))| 1] and phase cross-overfrequency [where <G(jw) = - 180]. You can use MATLAB command "margin" to obtain there quantities. iii) Calculate gain margin (in dB) and phase margin (in degrees) ·State whether the closed-loop is stable for K = 1 and briefly justify your answer based on the margin . (Gain marginPhase margin) iv. what happens to the gain margin and Phase margin when you increase the value of K?you You can use for loop in MATLAB to check that.Helpful matlab commands : if, bode, margin, rlocus NO COPIED SOLUTIONSarrow_forwardAuto Controls Hand sketch the root Focus of the following transfer function How many asymptotes are there ?what are the angles of the asymptotes?Does the system remain stable for all values of K NO COPIED SOLUTIONSarrow_forward-400" 150" in Datum 80" 90" -280"arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
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