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Homework Help: Tangential and Centripetal Acceleration

  1. Sep 11, 2013 #1
    1. The problem statement, all variables and given/known data
    A bike is travel up and over a hill with a radius at the top of the hill of 10 meters. The bike is traveling at 10 m/s at position A and 5 m/s at position. (and the problem comes with a picture showing an angle of 60* between point A and B.

    a. Determine the average tangential acceleration while slowing down
    b. Determine the centripetal acceleration
    c. Determine the net acceleration and its direction

    2. Relevant equations
    I used a(centripetal)=v^2/r and I was unsure of how to get tangential

    3. The attempt at a solution
    I evantually came out with a being equal to -2.5 m/s^2 (-5^2/10) and I was unable to get tangential just putting down my best guess which made it impossible for me to get a and c correct
  2. jcsd
  3. Sep 11, 2013 #2

    Andrew Mason

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    Is the cyclist applying force to the pedals as he goes up the hill? In other words, is the cyclist adding energy to the bike or is the bike coasting up the hill?

    I think you will have to provide the diagram or provide some more details of where A and B are in terms of horizontal and vertical distance from the top and base of the hill.

  4. Sep 11, 2013 #3
    This is the exact problem that was given to me. Sorry if some parts are hard to see the only relevant things I can think of that are in the picture and not the descriptionis that the radius of the circle is 10m and the angle between A and B is 60*

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  5. Sep 12, 2013 #4


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    Average acceleration means that constant acceleration which would result in the same change of velocity and distance travelled in the same time. Assuming constant tangential acceleration and the path taken as pi/3 R, and knowing the initial and final speeds, how do you determine the acceleration?

    As for the centripetal acceleration, the text does not specify if it is at A or B or at the maximum height.

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