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

A 1 175 kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the back of a 8 900 kg truck moving in the same direction at 20.0 m/s. The velocity of the car right after the collision is 18.0 m/s to the east.

(b) What is the change in mechanical energy of the car–truck system in the collision? (Use input values with an adequate number of significant figures to calculate this answer.)

m1 = 1175kg

m2 = 8900kg

v1i = 25m/s

v2i = 20m/s

vf = 20.583m/s

2. Relevant equations

K = 1/2mv^2

ME = U + K

U = mgh

3. The attempt at a solution

ΔK = (1/2m1v1f^2 + 1/2m2v2f^2) - (1/2m1v1i^2 + 1/2m2v2i^2)

am I on the right tracks?

if so how do i find v1f and v2f.

I know the relation:

20.583 = √(v1f^2 + v2f^2)

but there's 2 unknowns.

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

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

# Homework Help: Momentum of car and truck sytem.

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

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