The Life of a Star
1 mark · EasyWhat are the two main forces that balance each other during the main sequence period of a star's life?
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Gravitational force and outward pressure from nuclear fusion
Also accept: Gravity and pressure from fusion reactions; Gravity and outward force from fusion; Gravitational pull and outwards pressure
Common mistakes: Heat and light balance each other; Only gravity is involved
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Marking points
B1 · 1 mark · States both gravity (gravitational force) and outward pressure (from nuclear fusion).
Worked solution
The two main forces are gravitational force (acting inwards) and outward pressure from nuclear fusion reactions (acting outwards).