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# Mechanics Collision Problem watch

1. I'm in the middle of my 2nd year Uni exams, and this is for a mechanics class that I'm really struggling with so any help would be great!

A car of mass m1=1500kg is travelling due east at a speed of u1,0=20ms-1, when a second car runs into the side of it at a T-junction. The second car has mass m2=1000kg and is initially travelling due north at a speed of v2,0=25ms-1. The coefficient of restitution of the collision is e<1, and the forces involved in the collision all act in the north-south direction.

(a) Determine the velocity of each car immediately after the collision.
(b) How much kinetic energy is lost in the collision?

I done H and AH physics at school so was familiar with the concept of these collision problems but the class this year has made it so overcomplicated I'm really not sure how to even tackle them. Thanks for any help!
2. (Original post by Blue7195)
...
Can't help much, as I'm just going out.

I don't follow the meaning of the subscripts on your u,v. 1,0, and 2,0.

Since the only forces acting are North-South, there will be no effect on East-West motion.

So, split the working into East-West - nothing changes.

And North-South, standard one dimensional collision. Since e is not given, your answers will be a function of e.
3. (Original post by ghostwalker)
Can't help much, as I'm just going out.

I don't follow the meaning of the subscripts on your u,v. 1,0, and 2,0.

Since the only forces acting are North-South, there will be no effect on East-West motion.

So, split the working into East-West - nothing changes.

And North-South, standard one dimensional collision. Since e is not given, your answers will be a function of e.
Thankyou I got it now! Just find mechanics so difficult to get my head around

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