The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 0.023 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.048 kg and is initially at rest. The collision is not head-on. After the collision, the two pucks fly apart with the angles shown in the drawing.(adsbygoogle = window.adsbygoogle || []).push({});

http://www.webassign.net/CJ/07_32.gif

(Puck A is 65 degrees north of east, puck B is 37 degrees south of east.)

I used MaVa = MaVa(cos 65) + MbVb(cos 37), which gives me

.1265 = .0097202Va + .03833Vb. Since the total momentum in the Y direction was zero, I also used

Va(sin 65) = Vb(sin 37)

Va = .6640Vb or Vb = 1.506Va.

Every time I plug in those numbers I get a wrong value! Am I missing some important concept, or am I just making an algebraic error?

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# Homework Help: Momentum, elastic collision

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