Figure 7-28 shows three
forces applied to a trunk that moves leftward by 3.00 m over a friction-less floor. the force magnitudes are f1=5.00 n. f2 = 9.00 n, and f3 = 3.00 n. and the indicated angle of f2 is 30 degrees. during the displacement, (a) what is the net work done on the
trunk by the three forces and (b)
does the kinetic energy of the trunk increase or decrease?
figure 7-28 problem 15.