Inner sun (Sun 6) UF

Question 1

3 Mechanisms for energy transport

Answer 1

Conduction: heat spreads along a hot pan handle
Convection: hot air rises, such as from a radiator
Radiation: by infrared (etc) through a vacuum, for example from the Sun or by
putting your hand near a flame

Question 2

Where does fusion happen in the sun

Answer 2

centre to about 0.20-0.25 of the radius

Question 3

What temperature does fusion happen in the sun at

Answer 3

15 MK

Question 4

What density does fusion happen in the sun at

Answer 4

150*10^3 kgm^-3

Question 5

What is the power output of fusion in the sun

Answer 5

300 W m^-3

Question 6

What is the size of the radiation zone and the sinificance of this

Answer 6

Size: 0.2-0.7 of the radius
Optically thick: a photon will travel only a few mm before hitting an electron. That
means that it takes a long time for energy to make its way out of the radiation zone– more than 100000 years