Asolid plate, with a thickness of 15 cm and a thermal conductivity of 80 w/m·k, is being cooled at the upper surface by air. the air temperature is 10°c, while the temperatures at the upper and lower surfaces of the plate are 650 50 and 60°c, respectively. determine the convection heat transfer coefficient of air at the upper surface and discuss whether the value is reasonable or not for force convection of air.

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.