Question

Liquid helium us stored in container fitted with 7.00-cm -thick "superinsulation" consisting of numerous lavers of very thin aluminized Mylar sheets. The rate of evaporation of liquid helium in a 200-L container is about 0.700 L per day when the container is stored at room temperature (20 degree C). The density of liquid helium is 0.125 kg/L and the latent heat of vaporization is 21.0 kJ/kg. Estimate the thermal conductivity of the superinsulation. You are in charge of transporting a liver from New York, New York to Los Angeles, California for a transplant surgery. The liver is kept cold in a Styrofoam ice chest initially filled with 1.0 kg of ice. It is crucial that the liver temperature is never warmer than 5.0 degree C. Assuming the trip from the hospital in New York to the hospital in Los Angeles takes 7.0 h, estimate the R-value the Styrofoam walls of the ice chest must have. A container is filled to the brim with 1.4 L of mercury at 20 degree C. As the temperature of container and mercury is increased to 60 degree C, a total of 7.5 mL of mercury spill over the brim of the container. Determine the linear expansion coefficient of the material that makes up the container.

Answer 1

24%6 0 440 2 /s 21.0127 X 16"X2, 1 X 10"% 2 0 0 2.1267 J/s リ aide a A. ㅈ 5.8480 x10, m 2 0 5 8480 m 구 x10 -K 0.02126구