Question

A block whose mass is 650 gm is fastened to a spring constant K equals 65 N/m whose other end is fixed. The block is pulled a distance x = 11 cm from its equilibrium position at x = 0 on a smooth surface, and released from rest at t = 0. The maximum speed ‘S’ of the oscillating block is
1. 11 cm/sec
2. 11 m/sec
3. 11 mm/sec
4. 1.1 m/sec

Answer 1

Correct Answer - Option 4 : 1.1 m/sec

Maximum speed of spring will be at x = 0 when total spring energy will be converted into kinetic energy of mass

\(\begin{array}{l} \frac{1}{2}k{x^2} = \frac{1}{2}m{V^2}\\ \frac{1}{2} \times 65 \times {\left( {0.11} \right)^2} = \frac{1}{2} \times \left( {0.650} \right){V^2} \end{array}\)

V² = 1.21 m/s

V=1.1 m/s