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block a weighs 1.40 n, and block b weighs 4.20 n. the coefficient of kinetic friction between all surfaces is 0.30. find the magnitude of the horizontal force necessary to drag block b to the left at constant speed if a and b are connected by a light, flexible cord passing around a fixed, frictionless pulley.

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.