A 1 megaton nuclear weapon produces about 4*10^15J. How much mass must vanish when a 5 megaton weapon explode?

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Ways that industry and agriculture use physical properties to separate substances

Most short-period comets do not have randomly oriented orbits because