Water is boiled at atmospheric pressure by a horizontal polished copper heating element of diameter d = 5 mm and emissivity ε = 0.05 immersed in water. if the surface temperature of the heating wire is 350°c, determine the rate of heat transfer from the wire to the water per unit length of the wire.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

The higher the astm grain size number, the finer the gran is. a)-true b)-false