What happens when a penny is dropped from a height of 20 meters? a. it falls at a constant velocity b. its mass doubles for every second it falls c. the force of gravity causes it to accelerate d. it changes direction every 9.8 meters

I think it's either A or C because on B an object's mass can't change unless it is on a different planet, and on D it doesn't make sense unless the wind is blowing.

Ithink the answer is a

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.