tension force if the block is in water (density=1000 kg/m )? 3. Water flows through a horizontal pipe with a cross sectional area of 4m at a speed of 5 m/s with a pressure of 300,000 Pa at point A. At point B, the cross sectional area is 2 me. (a) What is the speed of water at point B? (b) What is the pressure at point B? on 4. At a given instant, the blood pressure in the heart is 1.6 x 10* Pa. If an artery in the brain is 0.45 m above the heart, what is the pressure in the artery? Ignore any pressure changes due to blood flow