A puck slides to the right at on a frictionless surface while a puck on the same line…

PHYSICS · Single correct · AP · Physics C: Mechanics · Force and Translational Dynamics · Force and Translational Dynamics

Problem

0.50\,\mathrm{kg}

puck slides to the right at

4.0\,\mathrm{m/s}

on a frictionless surface while a

0.25\,\mathrm{kg}

puck on the same line slides to the left at

8.0\,\mathrm{m/s}

. What is the speed of the center of mass of the two-puck system at this instant? (a)

+2.7\,\text{m/s}

(b)

-2.0\,\text{m/s}

(c)

0\,\text{m/s}

(d)

+5.3\,\text{m/s}