The work w done in moving an object from (0,0)(0,0) to (13,4)(13,4) subject to a constant force ff is w=f ⋅rw=f ⋅r, where rr is the vector with its head at (13,4)(13,4) and tail at (0,0)(0,0). the units are feet and pounds. (a) suppose the force f=8cosθi+8sinθjf=8cosθi+8sinθj. find ww in terms of θθ. (b) suppose the force ff has magnitude of 55 lb and makes an angle of π6π6 rad with the horizontal, pointing right. find ww in foot-pounds. (use symbolic notation and fractions where needed.)