(a) Three forces F1 = 2î+ k, F2 = 33+ 2k, F3 = î+ k act at points ri = î+2ĵ, r2 = 3î+ k, r3 = î+ î– 2k, respectively. (i) Find an equivalent system of forces consisting of a single force acting at the origin together with a couple. (ii) Find the equivalent wrench system consisting of a single force and couple with parallel torque. Find the wrench pitch and the equation of the wrench axis. Verify that the magnitude of the torque of the wrench couple is less than couple torque found in part (i). (b) A uniform disc of mass M and radius 3 m rolls without slipping down an inclined plane of vertical height 15 m. Assuming the disc starts from rest and rolls to the bottom of the plane, find the final angular velocity of the disc at the bottom of the plane. (Take the gravitational acceleration to be 10 ms-2.)