Question

Hyrdrostatic equilibrium in the sun means that:

(a) the sun does not change over time
(b) the Sun absorbs and emits equal amounts of energy
(c) pressure balances the weight of overlying layers
(d) energy produced in the core per unit time equals energy emitted at the surface per unit time

Answer 1

Hydrostatic equilibrium in the Sun means that the internal pressure caused by hot gases balances the gravitational forces trying to collapse the Sun, maintaining it in a stable state.

Step-by-step explanation:

Hydrostatic equilibrium in the Sun means that pressure balances the weight of overlying layers. This balance ensures that the Sun is stable and remains neither expanding nor contracting significantly over time. The internal pressure, driven by thermal gas (shown by red arrows in visual representations), tends to make the Sun expand, while the gravitational attraction (blue arrows) tends to make the Sun contract. When these two forces are perfectly balanced, the star is said to be in hydrostatic equilibrium, similar to a balloon that expands or contracts until the pressure inside and outside are balanced. The Sun has been in such an equilibrium state for billions of years, supported by the pressure of gases inside which, at the core, reach a temperature of 15 million K, high enough for protons to undergo fusion.