Question 7 (1 point) Saved A U-tube of uniform cross section is partly filled with water (density Pw). Another liquid of density p that does not mix with water is poured into one side until it stands a distance d above the original water level. The water level rises by a distance / in the other arm (see the figure below). If d = 9 cm and / = 4 cm, what is the density of the liquid relative to that of water, F ? p P P Your Answer: 1.4 Answer Question 8 (1 point) Estimate the total force with which Earth's atmosphere pushes down on all the oceans of the planet. The radius of Earth is roughly (6.4x10*3) km, and atmospheric pressure at sea level is roughly 101.3 kPa. Give your answer in N using scientific notation and to two significant figures. Question 9 (1 point) After descending for over two and a half hours, the Deepsea Challenger submarine reached the deepest point of the ocean floor in the Mariana Trench, 10.5 km below the surface. Since they needed to send a pilot in the craft, it was essential for the engineering team to know the maximum amount of force every part of the vehicle would feel when at this depth. Calculate the net force in units of kN exerted on the circular viewing port with a radius of 5 cm when Challenger was at the bottom of the Mariana Trench. Assume the water density, Pw, is 1030 kg/m everywhere and that the pressure on the inside of the submarine stays at atmospheric pressure