Question

If a load of 9 kg is suspended on a wire, the increase in length is 4.5 mm. The force constant of the wire is

• A. $0.49\times {10}^{4}N/m$
• B. $1.96\times {10}^{4}N/m$
• C. $4.9\times {10}^{4}N/m$
• D. $0.196\times {10}^{4}N/m$

Answer 1

The correct option is B $1.96\times {10}^{4}N/m$

$F=Kx$
$⟹K=\frac{F}{x}=\frac{9\times 9.8}{4.5\times {10}^{-3}}$
$=1.96\times {10}^{4}N/m$