A blue and a green billiard ball, each have a mass of 0.15 kg. Before they collide, the blue ball had a speed of 3 m/s while the green ball had a speed of -2 m/s. What direction are they traveling?

(1 point)
Responses

In opposite directions, away from each other.
In opposite directions, away from each other.

Not enough information is provided to determine the direction of travel.
Not enough information is provided to determine the direction of travel.

In opposite directions, towards each other.
In opposite directions, towards each other.

At a 90-degree angle to each other.
At a 90-degree angle to each other.
Question 2
What is the momentum of the blue and the green billiard balls respectively, before the collision, if each has a mass of 0.15 kg and the blue ball has a speed of 3 m/s and the green has a speed of -2 m/s?(1 point)
Responses

0.05 kg.m/s ; -0.075 kg.m/s
0.05 kg.m/s ; -0.075 kg.m/s

0.45 kg.m/s : -0.3 kg.m/s
0.45 kg.m/s : -0.3 kg.m/s

0.075 kg.m/s : 0.05 kg.m/s
0.075 kg.m/s : 0.05 kg.m/s

0.3 kg.m/s; 0.45 kg.m/s
0.3 kg.m/s; 0.45 kg.m/s
Question 3
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. what is the total momentum of the blue ball after the collision?(1 point)
Responses

1.0 kg.m/s
1.0 kg.m/s

0.45 kg.m/s
0.45 kg.m/s

-1.0 kg.m/s
-1.0 kg.m/s

0 kg.m/s
0 kg.m/s
Question 4
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?(1 point)
Responses

1.0 kg.m/s in the opposite direction from its original travel direction.
1.0 kg.m/s in the opposite direction from its original travel direction.

1.0 kg.m/s in the same direction from its original travel direction.
1.0 kg.m/s in the same direction from its original travel direction.

0.3 kg.m/s straight ahead
0.3 kg.m/s straight ahead

0 kg.m/s, sitting still.

1 answer

Let's go through each question step-by-step.

Question 1: Direction of travel of the balls

  • The blue ball is traveling at 3 m/s (positive direction), while the green ball is traveling at -2 m/s (negative direction). Since they have opposite speeds with one being negative, they are moving towards each other before the collision.
  • Correct response: In opposite directions, towards each other.

Question 2: Momentum of the balls before the collision

  • Momentum is calculated as \( p = m \cdot v \).
  • For the blue ball: \( p_{blue} = 0.15 \text{ kg} \cdot 3 \text{ m/s} = 0.45 \text{ kg.m/s} \).
  • For the green ball: \( p_{green} = 0.15 \text{ kg} \cdot (-2 \text{ m/s}) = -0.3 \text{ kg.m/s} \).
  • Correct response: 0.45 kg.m/s ; -0.3 kg.m/s.

Question 3: Total momentum of the blue ball after the collision

  • Since the blue ball stays in place after the collision, its speed is 0 m/s.
  • Thus, the momentum of the blue ball after the collision is \( p_{blue} = 0.15 \text{ kg} \cdot 0 \text{ m/s} = 0 \text{ kg.m/s} \).
  • Correct response: 0 kg.m/s.

Question 4: Momentum and direction of the green ball after the collision

  • Since the blue ball is stationary and the system conserves momentum, the total momentum before the collision (0.45 kg.m/s - 0.3 kg.m/s = 0.15 kg.m/s) must equal the total momentum after the collision.
  • The green ball takes on the momentum of the system, and we already determined that its direction of travel would be the same as its original direction (which was negative).
  • Given that the blue ball is stationary (0 kg.m/s), the green ball must have momentum of 0.3 kg.m/s but in the opposite direction as we previously established from conservation of momentum.
  • Correct response: 1.0 kg.m/s in the same direction from its original travel direction.

Overall, the responses are:

  1. In opposite directions, towards each other.
  2. 0.45 kg.m/s ; -0.3 kg.m/s.
  3. 0 kg.m/s.
  4. 1.0 kg.m/s in the same direction from its original travel direction.