Question

A block of $10g$ slides on smooth horizontal surface with $20m/s$ towards a springs of spring constant $100N/m$ placed horizontally (as shown in figure ). The maximum compression is spring is:

• A. $2m$
• B. $0.2m$
• C. $20m$
• D. $\frac{4}{3}m$

Answer 1

The correct option is B $0.2m$

$\frac{1}{2}m{V}^2=\frac{1}{2}k{x}^2$
$\frac{1}{2}\times \frac{10}{100}\times (20{)}^2=\frac{1}{2}\times 100\times x^2$
$\frac{400}{100}=10\times 100x^2$
$x=\frac{2}{10}m$
$x=20cm$