Which scientist studied physics in europe

Which statement best describes who the period and frequency of electromagnetic was change between gamma rays and microwaves? a) the period and frequency stay the same. b) the period increases and the frequency decreases. c) the period decreases and the frequency increases. d) the period increases and the frequency increases.

In order to place a satellite into orbit, it requires enough fuel to supply the necessary mechanical energy. into what types of mechanical energy does the fuel get transformed?

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?