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Centripetal Acceleration Outwards

  1. Apr 28, 2015 #1
    Hi. I have a question that I can't seem to figure out in my self study of physics. Why does centripetal acceleration point inward?

    When I drive around a corner, my body experiences a push away from the corner. I go that way, however, because of the car pushing me towards it. Not because of the centripetal acceleration, but because of its equal and opposite force.

    That's what my brain tells me anyway, but I must have a logical flaw somewhere, or else 99% of the physics community wouldn't disagree with me. Can anyone help me? Thanks :)
  2. jcsd
  3. Apr 29, 2015 #2


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    If no force were acting on you, you would have continued straight ahead. Since you follow the car around the corner, some force is necessary to make you change direction.
    What force? Equal and opposite to what?
  4. Apr 29, 2015 #3


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    The centripetal force is the force from your car seat that makes sure you follow the car. In an inertial system, it is the only force there is. It points to the center or you would end up turning in the other direction.

    The centrifugal force is an effect of your system being non-inertial and points outwards. In the system where the car is at rest, it is this force that explains why you are pressed to the away from the center of the motion. The force from the car seat now explains why you are not moving with respect to the car. Surely you feel that the car seat is pushing you in that direction. It is the same when you accelerate the car, the car seat will push you forward.

    In the same fashion, the floor pushes you up (not down) to counteract gravitational acceleration.
  5. Apr 29, 2015 #4
    Thanks @Orodruin! Your explanation was very helpful. Thanks also to @Svein!

    I didn't know the difference between centrifugal and centripetal and just used them interchangeably... Thank you guys!
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