Why does liquid helium form a gas when exposed to room temperature?

Find v1, the speed of the fluid in the left end of the main pipe. express your answer in terms of h1, h2, g, and either a1 and a2 or γ, which is equal to a1a2.

Ahypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.413 nm, 0.665 nm, and 0.876 nm, respectively. (a) if there are 8 atoms per unit cell and the atomic packing factor is 0.536, determine the atomic radius (in nm). (b) if the density is 3.99 g/cm3, calculate the metal's atomic weight (in g/mol).

Aseries circuit contains a 30 e resistor, a 20 resistor, and a 10 resistor. the power supply provides 100 v to the circuit the current in the 10 resistor, to two significant figures, is a.