Conservation of momentum on bike

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Momentum09
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Homework Statement



Tony (45kg) coasts on his bike (5kg) at a constant speed of 1 m/s, carrying a 5kg pack. Tony throws his pack forward, in the direction of his motion, at 5 m/s relative to the speed of bike just before the throw. What is the bike speed immediately after the throw?

Homework Equations



mv1 + mv1 = mv2 + mv2


The Attempt at a Solution



I combined Tony and the bike's mass together, 50kg. I then did
(50)(1) + (5)(1) = (50)(v) + (5)(5) and solved for v. However that wasn't correct. Can somebody please tell me what I did wrong?

Thank you so much!
 
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Momentum09 said:
at 5 m/s relative to the speed of bike

Relativity is your friend. :wink: