What happens when a star like the sun exhausts its core hydrogen supply?

Asubmarine has a "crush depth" (that is, the depth at which water pressure will crush the submarine) of 250 m. what is the approximate pressure (water plus atmospheric) at this depth? (recall that the density of seawater is 1025 kg/m3, g = 9.81 m/s2, and 1 kg/(ms2) = 1 pa = 9.8692 10-6 atm.) a. 34.8 atm b. 24.8 atm c. 25.8 atm d. 7.8 atm

What is created when solids,liquids,an gases mix with one another

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in