A blue and a green billiard ball, each with a mass of 0.15 kg, collide directly. Before the collision, the blue ball had a speed of 3 m/s while the green ball had a speed of -2 m/s. After the collision, the blue ball stays in place while the green ball continues in motion. What is the momentum and direction of the green ball?
To find the momentum and direction of the green ball after the collision, we first need to calculate the total momentum before and after the collision.
Before the collision:
Total momentum = (mass of blue ball x velocity of blue ball) + (mass of green ball x velocity of green ball)
Total momentum = (0.15 kg x 3 m/s) + (0.15 kg x -2 m/s)
Total momentum = 0.45 kgm/s - 0.3 kgm/s
Total momentum = 0.15 kgm/s
After the collision, since the blue ball stays in place, its momentum is 0 kgm/s. Therefore, the total momentum after the collision is equal to the momentum of the green ball.
Now, to find the momentum and direction of the green ball after the collision, we use the total momentum after the collision:
Total momentum = mass of green ball x velocity of green ball
0.15 kgm/s = 0.15 kg x velocity of green ball
Velocity of green ball = 1 m/s
Therefore, the momentum of the green ball after the collision is 0.15 kgm/s, and its direction is in the positive direction (since it continues moving to the right).