In the railroad freight yard, an empty freight car of mass m rolls along a straight level track at 1.0 m/s and collides with an initially stationary, fully loaded boxcar of mass 3.8m. The two cars couple together upon collision.(adsbygoogle = window.adsbygoogle || []).push({});

(a) What is the speed of the two cars after the collision?

This is the equation I have devised so far:

m1= M

m2= 3.8m

V1= 1.0 m/s

p2= 0

pf=p1 or (m1 + m2 )vf = (m1v1)

Vf = (m1)(1.0) / (m1 + 3.8)

I don't think this is correct. With the first mass being indicate as only m, I'm not sure how to compensate. Could someone please let me know what I'm doing incorrectly?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Does anyone get this?

**Physics Forums | Science Articles, Homework Help, Discussion**