A 49N block is pulled by a horizontal force of 50N along a rough horizontal surface at a constant acceleration of 6/m/s/s. what is the coefficient of friction

F=ma -----> sum of forces = ma, therefore sum of forces is 50 to the right minus frictional force to the left (opposite direction of the motion). Frictional force is f * 49N, where f is the coefficient of friction. Now put the equation together: 50N - (f * 49N) = (49N/9.8m/s/s) * (6m/s/s). Solve for f which is: 0.408