When compared with other fossils, what structure indicates that ancestors of whales used to walk on land?

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg

Why should the wavelength scale of spectroscope be calibrated

Why does the liquid rise up through the dip tube when the valve is open