# Momentum Collision

#### mohabitar

A blue car with mass mc = 438 kg is moving east with a speed of vc = 23 m/s and collides with a purple truck with mass mt = 1237 kg that is moving south with a speed of vt = 10 m/s . The two collide and lock together after the collision.

What is the angle that the car-truck combination travel after the collision? (give your answer as an angle South of East)

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I really have no idea how to approach this one. I've tried many combinations based off just random guesses, but none were right. Any ideas how I can begin this problem?

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#### Doc Al

Mentor
Why guess? You know, I'll wager, that's it's a momentum conservation problem. What does that tell you?

#### mohabitar

Well I've already figured out the individual momentums, but how do I figure out the angle? What values will I need to use, velocity or momentum?

#### Doc Al

Mentor
Well I've already figured out the individual momentums, but how do I figure out the angle? What values will I need to use, velocity or momentum?
What's the final momentum of the locked-together vehicles?

It's 15953.13

#### Doc Al

Mentor
Momentum is a vector. What is its direction?

South? Negative?

#### Doc Al

Mentor
South? Negative?
Figure it out. Hint: Let East be along the x-axis and North be along the y-axis.

#### mohabitar

Well I already knew that. Why does direction of momentum matter right now? I already know what direction the angle I'm looking for is. The question said "give your answer as an angle South of East"

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