C) Natural and Artificial sources
This is simply referring to the fact that the gravitational pull of the earth is greater as you get closer to the surface of the earth, meaning that acceleration increases as well.
Heat required = mass (g)*specific heat (c)* Temperature change (ΔT)
Given,
mass = 150 g, specific heat = 4.187 J/g.K, ΔT = -15 -(-30 = -15+30 = 15 K
Therefore,
Heat, H = 150*4.187*15 = 9420.75 J
Answer: proton, hydrogen nucleus, hydrogen atom
