Ball and inclined plane

  • Thread starter Faefnir
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Member advised to use the homework template for posts in the homework sections of PF.
A ball, which can be regarded as pointin all its effects, falls steady , subject only to the weight force, on an inclined plane of an angle α with respect to the horizontal from a height h computed from the impact point. The ball bounces elastically. Get the d height can reach the ball and the falling parabola characteristics after the impact


After impact vertical speed:

$$ v_{y} = \sqrt{2gh} \cos (2 \alpha) $$


Why ## \cos (2 \alpha) ##? There is a mathematical explanation for this? Yes, I know about vectorial speed components, but why exactly this corner?
 

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Doc Al
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What's the relationship between the angle of incidence and the angle of reflection when something bounces elastically off of a surface?
 
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angle of incidence = the angle of reflection
 
  • #4
Doc Al
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angle of incidence = the angle of reflection
Right! So draw yourself a diagram of the initial and final (pre and post collision) velocity vectors, showing the angle between them. Then find the vertical component of that final velocity.
 
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