An aluminum cube with side 20 cm floats on mercury. How much will the aluminum block sink when the temperature is increased from 270 K elvin to 320 Kelvin (the coefficient of mass expansion for mercury is 1.8.10^-4/Celcius)?

If a simple machine reduces the strength of a force, what must be increased?

Does the asteroid belt revolve around the sun?

Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 15°c. (b) what is the temperature at the center of cylinder a?