Physics

Problem

An argon atom of mass

m

travels to the right at

450\,\text{m}\!\cdot\!\text{s}^{-1}

and collides elastically and head-on with a krypton atom of mass

2m

that is initially at rest. What is the speed and direction of the argon atom immediately after the collision? a)

300\,\text{m}\!\cdot\!\text{s}^{-1}

to the right b)

150\,\text{m}\!\cdot\!\text{s}^{-1}

to the left c)

0\,\text{m}\!\cdot\!\text{s}^{-1}

(comes to rest) d)

450\,\text{m}\!\cdot\!\text{s}^{-1}

to the left