What is the height of the ball horizontally kicked (see figure)?

  1. flysky profile image84
    flyskyposted 5 years ago

    What is the height of the ball horizontally kicked (see figure)?

    ...if the angle alpha is 45 0 and the coefficient of friction is 0.21. Due to the friction the ball will stop after 1m.

    https://usercontent2.hubstatic.com/7644429_f260.jpg

  2. Ben Evans profile image73
    Ben Evansposted 5 years ago

    There are several assumptions.  The first is that when the ball hits the ground it does not have its velocity translated into rotational motion.  The vertical component of the velocity would make an inelastic collision with the ground.  It also needs to also not roll from the point of impact.  Without the first two assumptions, it would be impossible to solve without defining these.  Without the third assumption the ball would not stop.

    .21mgd=1/2m(Vx)^2 or Vx={(.42)(9.8)}^1/2=2 m/s
    At a 45 degree angle that would mean the Vy=2 m/s

    We know Vy we know g but we don't know time nor distance so we will use this equation:

    Vyf^2-Vyi^2=2gh

    The initial velocity in the y direction is 0 therefore h=4/{(2)(9.8)}=0.20 m

    1. flysky profile image84
      flyskyposted 5 years agoin reply to this

      Great answer and explanation!

 
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