Friction is a force that holds back the movement of a sliding object. You will find friction everywhere that objects come into contact with each other. The force acts in the opposite direction to the way an object wants to slide.
Answer:8 m/s
Explanation:
Given


kinetic Energy of 
initially
is at rest and let say
is moving with velocity u
kinetic Energy of 


In Completely inelastic collision both mass stick together and move with common velocity
Suppose v is the common velocity


therefore Final velocity with which both blocks moves is 1 m/s