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?

What is the increase in density of a medium due to wave travel?

Which body is in equilibrium? (1) a satellite orbiting earth in a circular orbit (2) a ball falling freely toward the surface of earth (3) a car moving with a constant speed along a straight, level road (4) a projectile at the highest point in its trajectory

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?