Acable that weighs 8 lb/ft is used to lift 750 lb of coal up a mine shaft 450 ft deep. find the work done. show how to approximate the required work by a riemann sum. (let x be the distance in feet below the top of the shaft. enter xi* as xi.) g

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i. e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion

Aperson touches a large chunk of ice with their hand and remarks, “this is making me cold.” explain what this person is feeling. is the ice transferring “cold” to the person? is there a heat transfer occurring? explain.