Physics

Problem

Sphere A of mass

0.40\,\text{kg}

slides frictionlessly to the right and collides elastically with stationary sphere B of mass

0.60\,\text{kg}

. After the collision, sphere A moves to the left at

0.40\,\text{m/s}

while sphere B moves to the right at

1.6\,\text{m/s}

. What was the speed of sphere A just before impact? a)

2.8\,\text{m/s}

2.0\,\text{m/s}

1.65\,\text{m/s}

4.0\,\text{m/s}