Answer
given,
mass of skier = 49 kg
angle made with horizontal = 13°
now,
a) skies velocity is constant
F x = m g sin θ -ma  Â
    a = 0
F x = 49 × 9.8 × sin 13°     Â
F x = 108 N Â Â Â Â Â
b) a = 1.2 m/s²    Â
F x = m g sin θ -ma    Â
F x =49 × 9.8 × sin 13° - 40 ×1.2
F x = 60 N Â Â Â Â Â Â Â Â
c) a = 2.4 Â Â Â Â Â
F x = m g sin θ -ma      Â
F x =49 × 9.8 × sin 13° - 40 × 2.4    Â
F x = 12 N Â Â Â Â Â Â