Question

A block of mass 10 kg is moving with speed 3 m/s collides with a spring connected to another block of mass 5 kg initially at rest. Find the compression in spring when both move with same speed

(1) 0.1 m 

(2) 0.2 m 

(3) 1 m

(4) 2 m

Answer 1

Correct option is: (1) 0.1 m 

\(v_f= \frac{10 \times 3}{15} = 2\ m/s\)

\(\frac{1}{2} k \ x^2 = \frac{1}{2} \times 10 \times 9 - \frac{1}{2} \times 15 \times 4\)

\(x^2 = \frac{30}{3000} = \frac{1}{100}\)

\(x = \frac{1}{10}m\)