Answer:
v₂ = 3.125 [m/s]
Explanation:
This problem and the given equation is the principle of linear momentum conservation where momentum is preserved before and after the collision.
On the left side of the equation is the momentum before the collision and the terms on the right after the collision.
[tex]m_{1}*v_{1}=m_{1}*v_{1}+m_{2}*v_{2}[/tex]
where:
m₁ = mass of the red cart = 2.5 [kg]
v₁ = velocity of the red cart before the collision = 4 [m/s]
m₂ = mass of the blue cart = 2 [kg]
v₁out = velocity of the red cart after the collision = 1.5 [m/s]
Now replacing:
[tex](2.5*4)=(2.5*1.5)+(2*v_{2})\\v_{2}=3.125[m/s][/tex]