Question

The force constant of a weightless spring is $16N/m$. A body of mass $1.0kg$ suspended from it is pulled down through $5cm$ & then released. The maximum kinetic energy of the system(spring $+$ body) will be?

• A. $2\times {10}^{-2}J$
• B. $4\times {10}^{-2}J$
• C. $8\times {10}^{-2}J$
• D. $16\times {10}^{-2}J$

Answer 1

The correct option is A $2\times {10}^{-2}J$

Given that,

Force constant, $K=16N/m$

Mass, $m=1Kg$

Elongation in the spring,

$x=5cm=0.05m$

Kinetic energy of the system is

$KE=\frac{1}{2}K{x}^2$

$KE=\frac{1}{2}\times 16\times {\left(0.05\right)}^2$

$KE=0.02J$

$KE=2\times {10}^{-2}J$