Explanation:
Step one:
given data
mass of red cart m1=0.5kg
initial velocity u1 of red cart=50cm/s
mass of blue cart m2=0.5kg
initial velocity u2 of blue cart= 0cm/s
final velocity v2 of blue cart= 40cm/s
final velocity v1 of red cart= 10cm/s
Step two:
Momentum values red cart before and after the collision.
Before collision
P1=m1u1
P1=0.5*50
P1=25kg•cm/s
After collision
P2=m1v1
P2=0.5*10
P2=5kg•cm/s
Change in momentum= P1-P2=25-5= 20kg•cm/s
Momentum values blue cart before and after the collision.
Before collision
P1=m1u1
P1=0.5*0
P1=0 kg•cm/s
After collision
P2=m1v1
P2=0.5*40
P2=20kg•cm/s
Change in momentum= P1-P2=0-20= -20kg•cm/s