In this problem they show a diagram of a pulley system with an inclined plane (25 degree incline). There is a box called m1=47kg resting on the incline plane and m1=35kg hanging on the vertical line. The question reads: The coefficient of friction between m1 and the surfvace of the inclined plane are Ustatic=0.42 and Ukinetic=0.19. a)if the masses are held in place and then released , will they start to move? ------> I know the answer is NO. b)how much mass would you have to add to m2 to cause the masses to begin to move? ----> The answer should be 2.8kg but I dont know how the book got this answer. c)If you said no to a) and added the mass that you calculated in b), what would be the acceleration of the masses? ---> answer given in the back of textbook is 5.7 m/s^2 ANY help with this problem would be greatly appreciated!! THANK YOU SO MUCH in advance :) For m1=47kg Fparallel=mgsin(25)=194.7N Fg=47*9.8=461N Fperpendicular=Fn=417N Ffk=uk*Fn=0.19*417=79N Applying Newton's 2nd law to m1 Fparallel-Ff-Ft=194.7-79-Ft=47*a For m2=35kg Fg=35*9.8=343N Apply Newton's 2nd law to m2 Ft-343N=35*a combine the two equations involving acceleration and cancelling out the force of tensions... this only leads us to an equation that ends up giving us a=-2.77m/s^2..... but this is where Im stuck... how do I find the mass required to get both masses to move?! can we assume the acceleration is equal to 1 when we are trying to determine the mass of m2, since they did not specify in the question?