On both the spring and fall equinoxes, the sun's rays are vertically overhead at the

It is overhead at the equator, it is because the sun ray’s will be moving vertically as this will be directed at the equator. It is because if it moves vertically, it will hit or overhead the equator and this usually happens in spring and fall.

scientific laws are the result of testing theories and proving them to be facts.

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s