Using a muscles full rage of motion when strength training is important for

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?

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

The center of the milky way most likely contains a. empty space. b. a red giant star. c. a globular cluster. d. a supermassive black hole.