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im having problem on a few questions all modeled around the same problem just with different numbers and different bits to work out so hopefully if someone can spot my error i will be able to get them all done

so the question is

Two identical particles are moving in the same straight line. Immediately before they collide, they are moving with speeds of 1m/s and 2m/s in the same direction. Given that the coefficient of restitution is 0.8, calculate the speeds of the two particles after the collision.

(Taken from the ocr m2 book if anyone has it handy)

now i labeled the particles B and A respectivly

B = 1m/s and A = 2m/s

for them to collide the diagram must be sumthing like

A--->B

or

B<---A

however i chose the top one cos im used to working left to right

now as far as i remember (hey im on holiday :P)

Rebound speed = E x Initial speed

where e is the coeffectient of restitution

therefore A's rebound speed should be

R = E x I

R = 0.8 x 2

R = 1.6

and B's

R = E x I

R = 0.8 x 1

R = 0.8

however when checking my answers i found the book told me 1.9m/s and 1.1m/s

can n e 1 spot my stupid mistake? >.<

thanks :)

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# Homework Help: Really easy problem >.<

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