Is Ignoring the Y-Component in Billiard Ball Collision Calculations Correct?

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SUMMARY

The discussion centers on the physics of billiard ball collisions, specifically addressing the importance of incorporating the y-component of velocity in calculations. The scenario involves a 0.50 kg cue ball colliding with a stationary 0.50 kg billiard ball, where the cue ball deflects at 1.2 m/s at an angle of 30.0°. The participant expresses doubt about their solution due to the omission of the y-component, calculated as 1.2sin30°. The consensus is that including this component is essential for accurate momentum conservation calculations.

PREREQUISITES
  • Understanding of momentum conservation principles (Pi = Pf)
  • Basic trigonometry for resolving vector components
  • Familiarity with collision physics in two dimensions
  • Knowledge of vector addition and subtraction
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  • Study the application of momentum conservation in two-dimensional collisions
  • Learn how to resolve vectors into their x and y components
  • Explore the physics of elastic and inelastic collisions
  • Practice solving problems involving glancing blows in billiard physics
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aatari
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Could someone please have a look at my solution and tell me if it makes sense. Although I am able to get the initial velocity that the question asked for, however the fact that I did not incorporate the y-component which is 1.2sin30 degrees into the solution makes me doubtful. If I do need to use that into the solution, how would that fit in? Please help!

1. Homework Statement


A 0.50 kg cue ball makes a glancing blow to a stationary 0.50 kg billiard ball. After the collision the cue ball deflects with a speed of 1.2 m/s at an angle of 30.0° from its original path. Calculate the original speed of the cue ball if the billiard ball ends up traveling at 1.6 m/s.

Homework Equations



Pi = Pf

The Attempt at a Solution


20171014_232649[43448].jpg


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aatari said:
Could someone please have a look at my solution and tell me if it makes sense. Although I am able to get the initial velocity that the question asked for, however the fact that I did not incorporate the y-component which is 1.2sin30 degrees into the solution makes me doubtful. If I do need to use that into the solution, how would that fit in? Please help!

1. Homework Statement


A 0.50 kg cue ball makes a glancing blow to a stationary 0.50 kg billiard ball. After the collision the cue ball deflects with a speed of 1.2 m/s at an angle of 30.0° from its original path. Calculate the original speed of the cue ball if the billiard ball ends up traveling at 1.6 m/s.

Homework Equations



Pi = Pf

The Attempt at a Solution


View attachment 213143
[/B]
In what direction do you think the second ball will go?
 

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