Question

playing in the street, a child accidentally tosses a ball at 18 m/s toward the front of a car moving toward him at 14 m/s . what’s the ball’s speed after it rebounds elastically from the car

Answer 1

The speed of the ball after it rebounds elastically from the car is 18 m/s.

Step-by-step explanation:

In order to determine the speed of the ball after it rebounds elastically from the car, we need to use the principle of conservation of momentum.

Let's assume the positive direction is towards the front of the car. The momentum before the collision is given by the sum of the momentum of the ball and the momentum of the car. The momentum of the ball is its mass multiplied by its initial velocity, which is (mass of the ball) * (initial velocity of the ball). The momentum of the car is its mass multiplied by its initial velocity, which is (mass of the car) * (initial velocity of the car). So the total momentum before the collision is (mass of the ball) * (initial velocity of the ball) + (mass of the car) * (initial velocity of the car).

After the collision, the ball rebounds elastically from the car. This means that the ball's velocity changes its direction but the magnitude of its velocity remains the same. So the ball's speed after it rebounds elastically from the car is equal to its initial speed, which is 18 m/s.