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B Ball bounce force direction

  1. Aug 9, 2016 #1
    When a ball is bounced against a wall at an angle why is that the wall only applies a normal force perpendicular to the collision location? Shouldn't the force applied by the ball against the wall be along the line at which it travels, at an angle? Then by that logic, by Newton's 3rd Law, shouldn't the wall's force be in the same direction?
     
  2. jcsd
  3. Aug 9, 2016 #2

    Bystander

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    Ideal or non-ideal collision?
     
  4. Aug 9, 2016 #3
    Ideal
     
  5. Aug 9, 2016 #4

    Bystander

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    Normal.
     
  6. Aug 9, 2016 #5

    Orodruin

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    In a collision without friction at the contact surface, there can be no force along the surface by definition.

    Real impacts have friction, but note that a force in the travel direction would make the ball bounce back in the direction it came from. This is not the typical observation, but you can often make a ball bounce back by giving it a back spin.
     
  7. Aug 9, 2016 #6
    Can't a force be applied on the wall's surface at an angle though?
     
  8. Aug 9, 2016 #7

    Bystander

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  9. Aug 9, 2016 #8

    Orodruin

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    Only if there is friction. It is the same as any other surface-surface interaction.
     
  10. Aug 9, 2016 #9
    Ok. Why is friction a minimal force in a non-ideal situation though? Ball bounces follow an almost perfect reflection trajectory.
     
  11. Aug 10, 2016 #10

    A.T.

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  12. Aug 10, 2016 #11

    sophiecentaur

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    In the context of Snooker / Billiards, the friction is a very relevant factor and that situation is one of the nearest to ideal. If it were not, there would be no point (it would be impossible to do) in giving a ball spin.
     
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