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Homework Help: Circular motion with car on hill

  1. Feb 25, 2009 #1
    1. The problem statement, all variables and given/known data

    A toy car with mass m=15.0g rolls without friction along a track that goes over a hill. The hill is in the shape of an arc of radius R=35.0cm. The center-of-mass (CM) of toy car is 0.5cm beyond the point of contact with the track. At the instant shown in the drawing its speed is 0.900m/s in the direction shown. Draw an accurate freepbody diagram of the toy car in the box and find all the following vector quantities indicated (both magnitude and direction). Clearly specify direction with respect to any unambiguous axis direction and make clear your choice of coordinate system. Show your work.

    2. Relevant equations
    The relevant equations are used in my attempt to solve this problem

    3. The attempt at a solution
    a. Fnet= Ftangential +FG= maT+mg
    b. a= Fnet/m= (maT+mg)/m = aT+g
    c. NT,C(Normal force by the track on the car)= -Fcentripetal=-mgsin30= -(0.015kg)(9.8m/s2)sin30
    d. Fcentripetal=mgsin30=(0.015kg)(9.8m/s2)sin30
    e. Ftangential=maT= (0.015kg)((0.800m/s2)2/0.35m)
    f. acentripetal=9.8m/s^2 (pointing toward center or circle)
    g. atangential= vT2/r= (0.800m/s2)2/0.35m

    I don't know if this is all correct.. but if it is... i have the free body diagram.... if it isn't... then i don't have the free body diagram and I don't understand what the Fnetwould be.... is there any other force on the car that i should know about?


    Attached Files:

  2. jcsd
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