Question

A block of mass 3 kg is in equilibrium with the help of three identical strings with one end of each string connected with the ceiling and other with the block and the angle between any two string is 120 and all the string makes an angle of 60 with the vertical. Find the tension in the string.

Answer 1

Final Answer : 20N

Steps:
1) 3-D Visualization is required in this question.
There is no Horizontal motion.
So, Tension in each string will be same due to symmetry.

2)
Tension in vertical Component :
$T \cos(60 \degree) .$
There are three strings.

$3T_y = Weight \:of\: mass \:3 \:kg \\ => 3T \cos(60 \degree) = 3g \\ => \frac{T}{2} = 10 \\ => T = 20N$

Hence, Tension in each string is 20N

Answer 2

Answer:

T = 20 N

Explanation:

please see the above attached photo

3strings therefore 3Tcos60