I need someone to give me brainliest and I will give you 25 more pints if you tell me who did it

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?

Aspectroscope breaks light up into its colors, allowing scientists to analyze light from the solar system and universe. by studying the spectral line patterns, widths, strengths and positions, scientists can determine the speed, position, and of celestial bodies. a) age b) origin c) rotation d) temperature

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.