$2.$ A $10$cm x $10$ cm x $10$cm block of steel $($steel $=7900$ kg$/$m$3)$ is suspended from a spring scale. The scale is in Newtons. a$.$ What is the scale reading if the block is in air?b$.$ What is the scale reading after the block has been lowered into a beaker of water and is completely submerged?$3.$ When analyzing a sample of ore, a geologist finds that it weighs $2\mathrm{.}00$ N in air and $1\mathrm{.}13$ N when immersed in water. What is the density of the ore? What assumptions did you make to answer this question?