givent aht
mass m = 423 kg
coeffiecient of friction ? = 0.0127
accleration due to gravity g = 9.8 m/s2
inclied angel ?2 = 4.51
inclined angel ?1 = 13.1
distance travelled d = 159 m
applied fore F = 535 N
the component of the force from the donkey in the direction of
motion is
   F
2 = F
1 cos?
1
        =521.08
N
from the free body diagram
 
?Fy = N - mg cos?2 = 0
    N = mg cos?2
       = 4132.56 N
?Fx = F2 - mg sin?2 - f =
ma
  here   f = ? N
              =
52.48
F2 - mg sin?2 - f = ma
a = F2 - mg sin?2 - f/ m
    = 0.337 m/s^2
work done by donkey
    W = F2 d
       =82851.72 J
work done by gravity
    W = - mg sin?2 d
        = -51828.53 J
work done by friction W = - fd
                                         
= - 8344.32 J