A mirror of weight 75N is hung by a cord from a hook on the wall. If the cord makes an angle of 30o with horizontal, the tension in the cord is
- 100N
- 1500N
- 250N
-
150N
The correct answer is: D
Explanation
2Ty = 75N
But Ty/T = adj/hyp = cos 60o
∴ Ty = T Cos 60o
=> 2Ty = 2Tcos 60o = 75N
2 x T x 0.5 = 75 => T = 75N
∴ Total tension in the rope = 2T.
= 2 x 75 = 150N