20 points will be given! !

which of the following boxes below represents a stable system? describe how a disturbance to this bow would affect it. use the terms center of mass and equilibrium in your response.

image below!

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

If a balloon is taken outside on a very cold day, what will occur?