"A racquetball of mass m = 43.3 g, initially moving at 40.0 m/s horizontally in the positive x direction, is struck by a racket. After being struck, the ball moves back in the opposite direction at an angle of 20.0° above the horizontal with a speed of 57.0 m/s. What is the average vector force exerted on the racket by the ball if they are in contact for 2.40 ms? (Assume the positive y direction is vertically upward. Express your answer in vector form.)"

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?