A 1 kg block of copper at 20 °C is dropped into a large vessel of liquid nitrogen at 77 K. How many kilograms of nitrogen boil away by the time the copper reaches 77 K? [ C cu = 387JKg-1°C-1, heat of vaporization of nitrogen is 2 ×105 J/Kg ]

Brass 0.030 m 5.0 µm Brass has linear thermal expansion coefficient a = 19 × 10-6rC . The picture shows a design defect in an electrical assembly: if the screw expands enough to touch the surface on the left, a dangerous short circuit will occur. The picture shows the assembly at 15°C. What is the maximum tempe ure the assembly can tolerate? 46.9°C 32.6°C 23.7°C 27.4°C 19.3°C

A glass tube of radius 0.80 cm contains liquid mercury to a depth of 64.0 cmat 12˚C. Find the depth of the mercury column at 100˚C. Assume that the linear expansion coefficient of the glass is 10x10-6 K-1and the linear expansion coefficient of mercury is 0.61x10-4 K-1.