A mass of 4 kg is suspended by a rope of length 4 m from a ceiling. A force of 20 N in the horizontal direction is applied at the mid-point of the rope as shown in figure. What is the angle which the rope makes with the vertical in equilibrium? Neglect the mass of the rope. Take g = l0 ${\mathrm{ms}}^{-2}$

 

• A

  ${\tan }^{-1}2$

• B

  ${\tan }^{-1}\left(\frac{1}{2}\right)$

• C

  ${\tan }^{-1}\sqrt{2}$

• D

  ${\tan }^{-1}\left(\frac{1}{\sqrt{2}}\right)$