The thermal conductivity of a certain solid material is k = 25 W/m K. At a certain point and time in a block of this material sketched in Fig.

P.1.1, the temperature is 65°C, the temperature gradient in the x direction is 0.20°C/m, and the cross-sectional area is 0.3 m².

(a) Determine the magnitude and sign of the heat transfer flux, q_x, in W/m².

(b) Determine the heat transfer rate, Q_x, in W.

(c) Convert the values of the temperature gradient to °F/ft and the values of q_x and Q_x to BTU/h ft² and BTU/h, respectively.

FIGURE P.1.1:

Transcribed Image Text:

T(x) = 65C Cross-sectional area, A = 0.3 m dT/dx = 0.2C/m