(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

In outer space a rock with mass 4 kg, and velocity < 4000, -2800, 3400 > m/s, struck a rock with mass 18 kg and velocity < 250, -290, 260 > m/s. After the collision, the 4 kg rock's velocity is < 3600, -2300, 3900 > m/s.

What is the final velocity of the 18 kg rock?

2. Relevant equations

Momentum Principle

pf = pi + Fnetdeltat

3. The attempt at a solution

Please help me if you can! Im pretty frustrated with this problem and I dont know why Im getting it wrong! I used the momentum principle, but it hasnt worked since this is a collision problem. Should I use that the final speed for the 18kg rock is v2f = 2(m/M)v1i

v2 being the final velocity of 18kg

v1 being the initial velocity of 4kg

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

Dismiss Notice

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: Collisions of rocks in space

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