Explanation:
Let the mass of two objects be m. Both objects move along the same line in opposite directions. Let v and uâ‚‚ are speeds of both objects before collision.
After the collision, both objects stick together and move with the speed of 0.1 V the direction of the velocity of the first mass before the collision.
Using the conservation of momentum as :
[tex]m_1u_1+m_2u_2=(m_1+m_2)v[/tex]
[tex]V=\dfrac{m_1u_1+m_2u_2}{(m_1+m_2)}[/tex]
[tex]V=\dfrac{m(u_1+u_2)}{(m_1+m_2)}[/tex]
[tex]0.1v=\dfrac{m(v+u_2)}{(2m)}[/tex]
On solving above equation, [tex]u_2=-0.8v[/tex]
So, the speed of the second mass before the collision is 0.8 v. The negative sign shows that the it moves in opposite direction. Hence, this is the required solution.