Physics

Problem

0.20\,\text{kg}

puck slides due east across frictionless ice at

4.0\,\text{m/s}

and strikes an identical puck that is initially at rest. The collision is elastic. After the collision, the first puck travels at

2.0\,\text{m/s}

at an angle of

60^{\circ}

north of east. What is the speed of the second puck immediately after the collision? a)

3.0\,\text{m/s}

4.0\,\text{m/s}

3.5\,\text{m/s}

2.5\,\text{m/s}