question_answer

A 1kg block collides with a horizontal weightless spring of force constant 2N/m. The block compresses the spring 4m from its rest position of the spring. If the coefficient of friction is 0.25, what was the speed of the block at the instant of collision?

A) 7.2m/s                          

B) 5.4 m/s

C) 6.4 m/s                         

D) 10 m/s