If two boxes, one with a mass of 4 kg and one with a mass of 10 kg are sitting on a shelf. Explain the differences in their amount of potential energy.

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings. 

The sun's gravitational pull is weaker on the planets that are closer to it, i think.

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.

A=v^2/r solve for r hope that