Question

A light spring of length 20 cm and force constant 2 kg/cm is placed vertically on a table. A small block of mass 1 kg fails on it. The length h from the surface of the table at which the ball will have the maximum velocity is-

• A. 20 cm
• B. 15 cm
• C. 10 cm
• D. 5 cm

Answer 1

The correct option is D 5 cm

Given data

Length of light spring $l=20cm=0.02m$

force constant $k=20cm$

man of the block $=1kg$

$h=\vartheta \sqrt{\frac{m}{k}}\Rightarrow \vartheta =\sqrt{\frac{m}{k}g}$

$h=\frac{m}{k}g$

$h=\frac{1kg}{2}\times 10=5cm$

$h=5cm$