Early scientists thought that the sun produced it's energy by

a) rotating b)expanding c) collapsing inward d) burning fuel? also,

scientists later thought that energy to heat the sun was released from a)gravity b) pressure c) globules d) kinetic energy? i suck in math and science :-/

The answer to question 1 is d. This is because in earlier times, the only thing that could explain something burning is burning wood or fuel. So the assumed that the sun did the same thing even though the were wrong. Question 2, the answer is none of the above. Heat is realeased because the sun is made up of hydrogen gas. These hydrogen gas atoms come together in a process known as nuclear fission and this releases heat and energy. This same process happens in a hydrogen bomb, so in a way you can think of the sun as one enormous hydrogen bomb in space.

Through the early 19th century the assumption was burning of fuel. By then they had calculated that if the Sun were a perfect mix of oxygen and carbon it would burn out (become pure CO2) in 30,000 years. Then they considered gravitational shrinkage, but this was limited to never being larger than the orbit of Mercury, and in any case such shrinkage would have been measurable over historic times. The discovery of radium led to the possibility of radioactivity, but with spectroscopes they knew the Sun has next to no radium. It was not until about 1950 that a University of Michigan astronomer named Subrahmanyan Chandrasekhar worked out the details of nuclear fusion where by the Sun combines 4 protons in a series of steps to create helium and a lot of energy.

Sorry I don't know the answer to question 1, but the scientists in the early days probably worried more about mapping the stars rather than discussing their energy sources

and for the second question, I think the sun's energy is produced by its nuclear fuel.

Energy in sun is produced by burning the fuel. Protons during collision produce a large amount of energy........so the fuels here are protons.
And sun does not heat itself, its already a source of heat energy.

Duh, the answer to the first is roast beef.


The second is kansas.


Vote for this for best answer, cuz its more informative than all others.

You need to use the book....... The answers are there. Just asking for answers and refusing to research will make you continue to suck at math and science.