Question

A block with a mass of $3\text{kg}$ is suspended from an ideal spring having negligible mass which stretches the spring by $0.2\text{m}$ at equilibrium. Find the force constant of the spring.

• A. $147\text{N/m}$
• B. $247\text{N/m}$
• C. $347\text{N/m}$
• D. $47\text{N/m}$

Answer 1

The correct option is A $147\text{N/m}$

Given,
Mass of block $\left(m\right)=3\text{kg}$
Elongation of spring $\left(x\right)=0.2\text{m}$
In equilibrium,
$mg=Kx$
$\Rightarrow K=\frac{mg}{x}=\frac{3\times 9.8}{0.2}=147\text{N/m}$