question_answer

A 1 kg block collides with a horizontal spring of force constant \[2\text{ }N{{m}^{-1}}\]. The block compresses the spring 4 m from the rest position of the spring. If the coefficient of friction is 0.25 between the block and floor, what is the speed of block at the instant of collision? (Take \[g=10\text{ }m\text{ }{{s}^{-2}}\])

A) \[7.2\text{ }m\text{ }{{s}^{-1}}\]         

B) \[\text{9}\text{.8 }m\text{ }{{s}^{-1}}\]         

C) \[\text{8 }m\text{ }{{s}^{-1}}\]           

D) \[\text{10 }m\text{ }{{s}^{-1}}\]