Recent content by Zobrox

  1. Z

    Hi i want to derive the 2nd equation of motion using the 1st

    will post shortly... just editing So first we know that velocity is the rate that distance changes, with respect to time: v = \frac{dx}{dt} if we rearrange the above, we get: (1) vdt = dx Now... we can represent the change in distance as (2) dx = x-x_{0}, where x_{0} is the initial distance...
  2. Z

    Solving for Block A's velocity: Va = 3.8 m/sThe correct answer is Va = 4.3 m/s

    Hmm, so your saying I shouldn't deduct the work due to weight with respect to block B? I thought that since the weight is opposing block B's motion this would be a negative work? I added the work due to weight from block B just to see, and it still doesn't yield the correct answer.
  3. Z

    Solving for Block A's velocity: Va = 3.8 m/sThe correct answer is Va = 4.3 m/s

    Thanks for your response haru, I feel it does answer my question... however I still am finding it hard to grasp the sign convention for everything... I have chosen up as positive for block B and down as positive for block A. This leads to a positive displacement for both block A and B right? so...
  4. Z

    Solving for Block A's velocity: Va = 3.8 m/sThe correct answer is Va = 4.3 m/s

    Okay, I'll write up my working now. I could approach it using kinematics, however it bugs me that I don't have a firm understanding on work energy, so would like to solve it this way :) Hope you can spot my errors when I update, thanks
  5. Z

    Solving for Block A's velocity: Va = 3.8 m/sThe correct answer is Va = 4.3 m/s

    Hi guys, really confusing myself over grasping this principle... I think my main problem is understanding datums and how choosing the direction of a positive axis effects the result. I understand that the work energy principle states: Wnet = ½m(vf2+vi2) I have previously been taught that Wnet...
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