A U-tube, open at both ends, is filled with water as shown on the left in the figure below. When filled with water the surface of the water is a distance x = 12.2 cm from the top of the tube in both arms. Without removing any water, mercury is poured into the left arm of the U-tube until the water level in the right arm of the U-tube reaches the top of the tube as shown in the figure on the right