A mass of 10 kg is suspended by a rope of length 4m, from the ceiling. A force F is applied horizontally at the mid-point of the rope such that the top half of the rope makes an angle of with the vertical. Then F (in newtons) equals: (Take and the rope to be massless):
Option: 1 100
Option: 2 75
Option: 3 70
Option: 4 10