Mammals evolved during the Triassic period. I believe the first mammal was like a tiny shrew-like animals. They called it the Eutherian. But the actually mammals were the dinosaurs.
No a scientific method is not used to to prove anything.
At the very top of the swing the velocity=0. If the velocity is 0 then the kinetic energy is 0 as well because kinetic energy is the energy of movement.
Quasars emit large amounts of radio energy.
The answer is The colors are added by the programmer to identify different elements in the molecule.