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  1. C

    Nodal voltages

    Thanks its coming together now. so my current = 20/9.93 = 2A I don't understand how to get degrees yet \phi = tan^{-1}\frac{y}{x} do I take 8.3/5,5 tan and then use above formula? what is the -1 how do i use on calculator?
  2. C

    Nodal voltages

    Here is a problem I got wrong, with the solution. I don't understand how they got answer. I don understand how you get 5.6 + j8.2 as 9.93 <55.67 how does 5.6 become 9.33 and j.2 = 55.67
  3. C

    Nodal voltages

    I'm confused on how to get proper result I have now I = 20V <20 degree/ 5.6+J8.2 and I found in book the way to draw circuit. but I don't understand how to use the equation with cos and j 20 sin.
  4. C

    Nodal voltages

    So if I need to find E/Z = 20/9.9 = 2A Now all I do is redraw circuit with 2A current source with impedance parallel in circuit?
  5. C

    Nodal voltages

    Ok I'm reading that chapter now, I attached a sample I'm working on now.
  6. C

    Nodal voltages

    Yea I was there today, will be back tomorrow.
  7. C

    Nodal voltages

    Can someone direct me to a tutorial for solving network nodal voltages. Also need to learn how to convert voltage source to a current source.
  8. C

    Frequency Equation

    Ok, I'm checking myself with text that has answers in back for just odd numbers. the only answer they give is 2500/pi Hz but the true answer is to go another step and divide the 2500 by pi. ok thanks.
  9. C

    Frequency Equation

    So are you stating I should have as an answer 5000/2 pi the freq = 2500 pi Hz
  10. C

    Frequency Equation

    So my freq = 5000Hz and my Amplitude = 50V.
  11. C

    Frequency Equation

    I’m really struggling here, if A = 50 and wt = 5000 If I want to know freq should I take the sin of 50(0.7666) and then multiply that by 5000 I have 10 problems I need to lean how to use this equation.
  12. C

    Frequency Equation

    Vs = A*sin({\omega}t + {\phi})+C this formula states Vs = Using the information I'm given 50 * sin(wt + 0) + C is that the sin of 5000t I'm confused on this I never used this type of equation before.
  13. C

    2KVA transformer how do I determine the max. safe primary current.

    If I have 2KVA transformer how do I determine the max. safe primary current.
  14. C

    Frequency Equation

    Then do I take the sin of 50 then times that by 1/5000t?
  15. C

    Frequency Equation

    If I'm given v=50 sin(5000t) how do I determine the frequency or amplitude? Can someone direct me to a source? thank you
  16. C

    Charge Help

    Can someone let me know if I'm going in the right direction. The electrical force on a 2-columb charge is 60 newtons, What iis the magnitude of the electric field? E =f/q E= 60/2 E=30 If a charge of +3 x 10 -6columbs sets up an electrical field, find: a. The magnitude of...
  17. C

    Electric Potential vrs Electric Potential Energy

    I'm trying to grasp the concept between Electric Potential and Electric Potential Energy. A charge object has an electric potential, and electric potential = electric potential energy/charge I still can't explain the difference between the two(Electric Potential vrs Electric...
  18. C

    Review for Test

    I can't find formula for determing the number of rotations a wheel makes in one minute. Diameter = 26" Traveling at 20 feet per second. is there a formula for RPM? Also need the formula to determine angular velocity. thanks
  19. C

    Formula for finding the period of a pendulm?

    T = 2*pi * Sqrt 1/g Is this the proper formula for finding the period of a pendulm? The length = 0.9 meters g= 9.8m/s^2 I come up with 1.90s.. am I going in right direction?
  20. C

    A motorcyclics performing a stunt - How long is he in the air?

    A motorcyclist intends to perform a stunt in which he jumps a 25meter wide river. The motorcyclist must jump from a cliff on one-side 20 meters lower than the other side. The motorcyclist approaches the cliff at 50m/s What formula should I use to solve for the Horizontal direction...
  21. C

    Angular Velocity Review

    They are the same.
  22. C

    Angular Velocity Review

    A Ferris wheel has a radius of 8 meters and rotates once every 15 seconds. A 10:1 scale model of the Ferris wheel also rotates once every 15 seconds. Which has the higher Angular Velocity? Solution: angular velocity = Change in rotation/change in time Do I use the formula v = rw...
  23. C

    Acceleration of Pail Problem

    Problem: What is the acceleration of a 20kg pail of cement that is pulled upward (not sideways) with a force of 300N. let g= 10m/s^2 Answer: 20kg*10m/s^2 = 200N a = (300N-200N)/20kg a = 5m/s^2 The book gives me the answer as 2m/s^2... did I miss something? I beleive this to be a...
  24. C

    Why is it hard to walk without bending your knees?

    In the terms of rotational inertia why is it hard to walk without bending your knees? The greater the bulk of the object mass to its axis the greater its rotational inertia. how can I relate that to walking without bending knees? I understand that with rotational inertia an object...
  25. C

    Linear Speed/Rotational Speed

    Thanks to all. I now understand v=w*r v= linear speed w= Rotational Speed r=radius
  26. C

    Linear Speed/Rotational Speed

    I can define both terms Linear Speed, Rotational speed, but I need to find the formula difference so I can show how rotational speed is changed to linear Speed. I can not find the formula for either.
  27. C

    Kinetic Energy

    Thanks, I was searching for an answer that I would never find.
  28. C

    Kinetic Energy

    So are you saying I should: 1/2 mv^2 = mgh 1/2 v^2/g=h 1/2(10^2/9.8)=5.1m The text book I have in no way explains this, if this is correct where can I get other sources of help on physics
  29. C

    Kinetic Energy

    The question is: If a sprinter running at 10 meters per second could convert his kinetic energy into upward motion, how high could he jump? How do I solve this if I use the KE = 1/2 mv^2 I dont know what the mass is?
  30. C

    Potenital Energy

    thanks I feel a sleep on the job, again.
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