Recent content by Kirasagi

  1. K

    Electric Field in a Square Problem

    Thanks for the reply! All along I was doing my math wrong on adding the electric field vectors. As r = (sqrt2/2)a e = kq/(r^2) e = kq/(a^2/2) e = 2kq/(a^2) for each vector on one side. Since there's 2 vectors on each side then it equals to 4kq/(a^2) Combining the vectors using...
  2. K

    Electric Field in a Square Problem

    Homework Statement I think it would be better if I put the picture. Additional questions: Find the direction of the electric field. Find the magnitude of electric field due at C due to charges A, B, and D. Homework Equations Pythagorean Theorem. E = kq/r^2 The Attempt at a Solution For...
  3. K

    Elevator at rest compared to when its accelerating

    I see. It just hit me that a weighing scale shows the normal force and not the gravitational force. So I did my work right, just not the final answer! mg = Fn + .4mg Fn = mg - .4mg, which then becomes .6. Got it. Thanks again!
  4. K

    Elevator at rest compared to when its accelerating

    Homework Statement When the elevator is at rest, the scale reads W. Suppose the elevator now accelerates down-ward at a constant rate of 0.4 g. What is the ratio of the new scale reading to the value W of the scale reading when the elevator is at rest? Homework Equations Force...
  5. K

    Pendulum speed given length and angle

    Got it right on my last try. Thanks!
  6. K

    Pendulum speed given length and angle

    Would that be Lsinθ? so v = √g*Lsinθ*tanθ v = 1.52234 m/s
  7. K

    Pendulum speed given length and angle

    I see, this was the way I saw it at first but I thought it's more complicated. So: Fx = Tsinθ = mv^2/r Fy = Tcosθ = mg T = mg/cosθ; plugging that in for Fx.. mv^2/r = mgtanθ, so.. v = √rgtanθ, where r = Length ? Not sure if I derived everything correctly. Assuming I did everything right...
  8. K

    Pendulum speed given length and angle

    To be honest I'm not really sure, I don't remember paying attention to pendulums too much. I'm assuming it also rotates/spins as it moves? Not sure what can I tie with that. Am I doing this problem the right way? But having that idea, maybe I should add rotational kinetic energy?: 1/2mv^2...
  9. K

    Pendulum speed given length and angle

    Homework Statement A circular pendulum of length 1.2 m goes around at an angle of 25 degrees to the vertical. Predict the speed of the mass at the end of the string. Use g = 9.8 m/s2. Answer in units of m/sHomework Equations 1/2mv^2 = mgh h = L - Lcosθ The Attempt at a Solution I used the...
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