Assuming this coin is on earth and that it wasn’t dropped forcefully:
Use the formula d = 1/2at^2. Rewriting using a=g and solving for height h gets us h = 1/2(9.8)t^2.
In this case that would get that the change in height h is 0.5(9.8)(0.3^2) = 0.441 m.
Explanation:
Understanding that stars are naturally quite hot, imagine I pulled a piece of hot iron from a furnace. It would glow a bright red, and then slowly fade to black as the iron cools.
White dwarfs glow for the same reason - they are HOT!
Process is called condensation and it happens when heat is removed from gaseous system.
