A long, cylindrical, electrical heating element of diameter D = 12 mm, thermal conductivity k = 240 W/m ⋅ K, density rho = 2700 kg/m3 , and specific heat cp = 900 J/kg ⋅ K is installed in a duct for which air moves in cross flow over the heater at a temperature and velocity of 30°C and 8 m/s, respectively. (a) Neglecting radiation, estimate the steady‐state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1000 W/m. (b) If the heater is activated from an initial temperature of 30°C, estimate the time required for the surface temperature to come within 10°C of its steady‐state value.

how is this a question? in order for me to answer it i have to understand the question

explanation:

the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true?

a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of

5

9

degree celsius.

a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.

a temperature increase of

5

9

degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.

a) i only

b) ii only

c) iii only

d) i and ii only

answer: report them

explanation:

answer:

a

explanation: