Question

In the setup shown, a 200 N block is supported in equilibrium with the help of strings and a spring. A point O, the strings knotted. Extension in the spring is 4 cm. Force constant of the spring is closest to
$[g=10m/s^2]$

• A. 30 N/m
• B. 2500 N/m
• C. 3000 N/m
• D. 4000 N/m

Answer 1

The correct option is C 3000 N/m

By law’s theorem-

$\frac{T_1}{\sin 127}=\frac{T_1}{\sin 143}=\frac{200}{\sin 90}$

$\frac{T_2}{\sin 143}=\frac{200}{\sin 90}$

$T_2/\sin \left(180-{37}^0\right)=200$

$\frac{5}{3}{T}_2=200$

$F=kx$

$120=k\left(4\times {10}^{-2}\right)$

$k=3000n/m$