Some researchers believe that the dinosaur Barosaurus held its head erect on a long neck, much as a giraffe does. If so, fossil remains indicate that its heart would have been about 12.0 m below its brain. Assume that the blood has the density of water, and calculate the amount by which the blood pressure in the heart would have exceeded that in the brain. Size estimates for the single heart needed to withstand such a pressure range up to two tons. Alternatively, Barosaurus may have had a number of smaller hearts.

From negative to negative

Answer;

hot magma rises and pushes up toward the lithosphere, and as it cools it cycles back down toward the core to be heated again.

explanation; convection currents are the circular pathways taken by a fluid that enhances heat transfer by the process known as convection which occurs in fluids.convection currents transfer heat from one place to another by mass motion of a fluid. earth mantle is in a semi-liquid state and behaves like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from heat of the earth's core, as the rock loses heat into the earth's crust it becomes cooler and more dense, then sinking back down to the core, then repeating the cycle.