A `16kg` block moving on a frictionless horizontal surface with a velocity of `4m//s` compresses an ideal spring and comes to rest. If the force constant of the spring be `100N//m`, then how much is the spring commpressed ?

Explanation

`K.E. ` of block `=` work done in compressing the spring `(1)/(2)m upsilon^(2)=(1)/(2)k x^(2)`
`x=sqrt((m upsilon^(2))/(k))=upsilonsqrt((m)/(k))=4sqrt((16)/(100))=1.6m`