What is the Final Velocity of the 18 kg Rock After Collision in Space?

AI Thread Summary
The discussion revolves around calculating the final velocity of an 18 kg rock after a collision in space with a 4 kg rock. The initial velocities of both rocks are provided, along with the final velocity of the 4 kg rock post-collision. Participants emphasize the use of the momentum principle, stating that the total momentum before the collision must equal the total momentum after. There is confusion regarding the application of the momentum principle in collision scenarios, with suggestions to express velocities in vector form and apply the equation P_i = P_f. The overall goal is to determine the final velocity of the 18 kg rock accurately.
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Homework Statement



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?

Homework Equations



Momentum Principle

pf = pi + Fnetdeltat

The Attempt at a Solution



Please help me if you can! I am pretty frustrated with this problem and I don't know why I am 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
 
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Hi, Write the velocities in vector form. Like for 4 Kg rock, initial velocity will be

V_4=4000i-2800j+3400k

Then apply

P_i=P_f
 

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