Which pair of sentences is describing the same velocity?

Avalue that describes how heavy an object is and is related to the force of gravity is

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?

Ineed ! using proper grammar, spelling, and punctuation, write at least one 5 sentence paragraph describing 3 ways we use the elements of the electromagnetic spectrum (ems) in our everyday lives.