Thin electrical heater is wrapped around the outer surface of a long cylindrical tube whose inner surface is maintained at a temperature of 5°c. the tube wall has inner and outer radii of 40 and 90 mm, respectively, and a thermal conductivity of 10 w/m·k. the thermal contact resistance between the heater and the outer surface of the tube (per unit length of the tube) is 0.01 m·k/w. the outer surface of the heater is exposed to a fluid with [infinity] -10°c and a convection coefficient of 100 w/m2·k. determine the heater power per unit length of tube required to maintain the heater at 25°c.

Agas initially at p1 = 1 bar and occupying a volume of 0.5 liter is compressed within a piston–cylinder assembly to a final pressure p2 = 4 bar. (a) if the relationship between pressure and volume during the compression is pv = constant, determine the volume, in liters, at a pressure of 3 bar. (b) repeat for a linear pressure–volume relationship between the same end states. reference

A250-n box is at rest on a frictionless horizotal floor. then a person shoves the box with a non-zero force of magnitude p. which statement best describes the relationship betweeen p and the motion of the box after it was shoved? -the box will not move when p< 250n but otherwise will accelerate at a constant rate that is directly proportional to p - the box will begin moving at a speed that is directly proportional to p, then will gradually slow to a halt -the box will move with constant velocity at a speed that is directly proportional to p -box will accelerate across the floor at a constant rate that is directly proportional to p

Which describes increasing the efficiency of energy resource