The density of ice is 0.92gm/cm3. A piece of ice has length 50cm, breadth 30cm and height 20cm. Find out the mass of water displaced by the ice when it is kept in water. (density of water= 1 gm/cm3)

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.