Answer:
v₃ = 6.67 [m/s]
Explanation:
To solve this problem we must use the linear momentum conservation theorem, which tells us that momentum is preserved before and after the collision.
Let's take the ball movement of 8 [kg] as positive.
Therefore we can built the following equation:
[tex](m_{1}*v_{1})+(m_{2}*v_{2})=(m_{1}+m_{2})*v_{3}[/tex]
where:
m₁ = mass of the 8 [kg] ball
m₂ = mass of the 4 [kg ] ball
v₁ = velocity of the 8 [kg} ball before the colllision = 10 [m/s]
v₂ = velocity of the 4 [kg] ball before the colllision = 0 [m/s] (at rest)
v₃ = velocity of the two balls after the collision [m/s]
[tex](8*10)+(4*0)=(8+4)*v_{3}\\80 = 12*v_{3}\\v_{3}=6.67 [m/s][/tex]
