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Calculating G Using an Inclined Track

  1. Oct 2, 2011 #1
    I need to experimentally find gravity using information from a lab we finished last week. Should I not be getting 9.8 m/s² at each angle or am I doing something wrong? And if I should indeed be getting ≈9.8 m/s² as my y-acceleration, can you point me in the right direction?
  2. jcsd
  3. Oct 2, 2011 #2
    You can get more help if you give a diagram of the apparatus used and the measurements taken.
  4. Oct 2, 2011 #3
    Sorry for being unspecific, I was looking more for a general answer. But we had a cart travel down a sloped track, had times recorded at A and B, along with a time taken to travel from A to B, all of which were known distances. This was used to calculate v1, v2, and a. Then we had taken two height measurements 60cm apart, and used this to find the angle of the track to the table. Then I multiplied the calculated acceleration by sine of the angle to get y-acceleration. Basically should this y-acceleration be ≈9.8 m/s/s or should it be proportionally related like y-acceleration/angle = g/90?
  5. Oct 2, 2011 #4
    Were there any other forces parallel to the track besides a component of the weight of the cart?
  6. Oct 2, 2011 #5
    Nothing was applied to the cart directly, it was just set at the top and then released. Obviously there are factors of friction and air resistance, but this is the third week of a high school mechanics course and we're limiting everything to kinematics.
  7. Oct 2, 2011 #6
    If friction is negligible (eg air track) then the measured acc will be gsin(angle between track and horizontal)
  8. Oct 2, 2011 #7
    Okay, that gives me more consistent results. I had been solving for g by g=asin.
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