An argon atom of mass travels to the right at and collides elastically and head-on…

PHYSICS · Single correct · AP · Physics 1: Algebra-based · Linear Momentum · Linear Momentum

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