A 2.0-kg ball rolls to the right at 3.0 m/s. A 4.0-kg ball rolls to the left at 2.0 m/s . What is the momentum of the system after a head-on collision of the two balls?

Final momentum after a head on collision is -2kgm/s

Explanation:

         One ball moves to the right and the other moves opposite  and momentum is a vector quantity so that considering the direction

Initial momenta are        P₁=2x3=6kgm/s        P₂=4x(-2)=-8kgm/s      

Final momentum is the vector sum of P(final)= 6-8= -2 kgm/s

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.