Enter your answer in the provided box. in water conservation, chemists spread a thin film of certain inert materials over the surface of water to cut down on the rate of evaporation of water in reservoirs. this technique was pioneered by benjamin franklin three centuries ago. franklin found that 0.10 ml of oil could spread over the surface of water of about 32.0 m2 in area. assuming that oil forms a monolayer (that is, a layer that is only one molecule thick) estimate the length of each oil molecule in nanometers. assume that oil molecules are roughly cubic. (1 nm = 1 × 10−9 m)

Review multiple-concept example 7 in this chapter as an aid in solving this problem. in a fast-pitch softball game the pitcher is impressive to watch, as she delivers a pitch by rapidly whirling her arm around so that the ball in her hand moves in a circle. in one instance, the radius of the circle is 0.626 m. at one point on this circle, the ball has an angular acceleration of 66.1 rad/s2 and an angular speed of 12.6 rad/s. (a) find the magnitude of the total acceleration (centripetal plus tangential) of the ball. (b) determine the angle of the total acceleration relative to the radial direction.