Energy in a spring:
E = 0.5 * k * x²
k spring constant = 800 n/m
x stretch of the spring = 5 cm = 0.05 m
E = 0.5 * 800 * 0.05² = 1
C. hydrogen accreted onto a white dwarf from a close companion rapidly fuses to helium, releasing a large amount of energy.
The accreted material, composed mainly of hydrogen, is compacted on the surface of the white dwarf due to the intense gravitational force on that place. As material accumulates, The white dwarf becomes increasingly hot, until it reaches the critical temperature for ignition of nuclear fusion.
-- What's the volume of a cylinder with radius=1m and height=55m ?
( Volume of a cylinder = π R² h )
-- How much does that volume of water weigh ?
1 liter of water = 1 kilogram of mass
Weight = (mass) x (acceleration of gravity)
-- What's the area of the bottom of that 1m-radius cylinder ?
Pressure = (force) / (area)
The density of ice is less than the density of water. C
