The total kinetic energy of two cars is measured before and after they crash into each other. The total kinetic energy of the two cars after the crash is less than the total kinetic energy before the crash. Which of the following best explains the loss of kinetic energy

A. The car with more mass gave up its kinetic energy to the car with less mass.
B. Some of the cars' kinetic energy was converted to sound and heat energy.
C. Both of the cars were being pulled downward by the force of gravity.
D. Energy in a system is always lost.

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.

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