Estimate the convective heat-transfer coefficient for natural convection from a horizontal steam pipe. The outside surface temperature of the insulated pipe is 80°C. The surrounding air temperature is 25°C. The outside diameter of the insulated pipe is 10 cm. please help me if my answer is wrong

A glass window of width W = 1 m and height H = 2 m is 5 mm thick and has a thermal conductivity of k 1.4 W/m K. If the inner and outer surface temperatures of the glass are 15°C and -20°C, respectively, on a cold winter day, what is the rate of heat loss through the glass? To reduce heat loss through windows, it is cus- tomary to use a double pane construction in which adjoining panes are separated by an air space. If the spacing is 10 mm and the glass surfaces in contact with the air have temperatures of 10°C and -15°C, what is the rate of heat loss from a 1 m x 2 m window? The thermal conductivity of air is k, = 0.024 W/m.K.

5. A laboratory water bath has an immersed horizontal (cylindrical) water element, 2.54 cm. in diameter and 35cm in length, with a power input of 500 W. If the bulk water temperature is 40 °C and heat transfer occurs by free convection only, calculate the surface temperature of the heater.

Estimate the natural convection heat transfer coefficient of the horizontal pipe. The temperature of the outer surface of the pipe is 120 ° C. The ambient air temperature is 25 ° C. The outer diameter of the pipe is 10 cm. Convection coefficient = Answer W / m² ° C.