Recent content by Jess_18033152

  1. J

    Change in Capacitor for largest possible Current

    Homework Statement The capacitor is changed so that the largest possible current is supplied by the source. Enter the value of the capacitive reactance when this change is made. Give your answer in Ohms (Ω). A unit is not required with your answer. Homework Equations The circuit is powered by...
  2. J

    What is the Resistance of the Patient in a Defibrillation Shock?

    This question follows: <https://www.physicsforums.com/threads/charge-stored-on-a-capacitor.948193/>
  3. J

    What is the Resistance of the Patient in a Defibrillation Shock?

    Homework Statement When the defibrillation shock is applied, the capacitor discharges through the patient as shown in the diagram below: The fraction of charge remaining on the capacitor 1.00 ms after it begins discharging is 0.300. Calculate the resistance of the patient. Note: This will...
  4. J

    Charge Stored on a Capacitor

    Homework Statement Defibrillation[/B] is a common treatment for life-threatening cardiac arrhythmias and ventricular fibrillation. The defibrillator applies a current across the heart (shown by the red arrows in the image below) for a short time (a few milliseconds), disrupting the arrhythmia...
  5. J

    What is the net charge on a magnesium ion after losing two electrons?

    Homework Statement Calculate the net charge on a magnesium ion which has lost two electrons. 2. The attempt at a solution I put 2+ as my answer and this is what I was told, but I don't understand what they mean by the following; That's a chemist's shorthand, not the amount of charge on the...
  6. J

    Plane Mirror - Distance to Focus for Clear Selfie

    The image is 2 x the distance from the mirror so my answer would be 2 x 3.05 = 6.1 m
  7. J

    Plane Mirror - Distance to Focus for Clear Selfie

    Would this mean that I need to use the following equation instead? 1/d0 + 1/di = 1/f ?
  8. J

    Plane Mirror - Distance to Focus for Clear Selfie

    All I've been given for this question is what I gave you. di is the distance the image is seen from the mirror. The camera is held by the said person taking the picture. I assume distance from the mirror to focus?
  9. J

    Calculating Image Distance Using a Christmas Tree Ball

    Homework Statement You look at yourself in a shiny Christmas tree ball, which has a diameter of 9.63 cm. If your face is 7.81 cm away from the shiny ball, calculate the image distance. Homework Equations ? Thinking I would use magnification = di/d0 di = 0.0781m d0 = 0.0963m The Attempt at a...
  10. J

    Plane Mirror - Distance to Focus for Clear Selfie

    Homework Statement Suppose that you want to take a mirror selfie, standing 3.05 m in front of a plane mirror. Calculate the distance that the camera will focus to, to get a clearly focused image of your beautiful self. Homework Equations d0 = diThe Attempt at a Solution Would I be correct in...
  11. J

    How Is the Distance to the Seabed Calculated Using Sonar?

    Yes, it's half the time because we are only want the time to get to the sea bed, whereas we were given the time to reach the seabed and come back to the boat.
  12. J

    How Is the Distance to the Seabed Calculated Using Sonar?

    The answer was using: 1480 x (1/2 x 0.461) = 341 m
  13. J

    Time for radio signal to get to a receiver

    Sorry the answer was 5.83 x 10^-5 s hahah :), thank you.
  14. J

    How Is the Distance to the Seabed Calculated Using Sonar?

    Homework Statement A depth sounder on a ship measures the distance between the bottom of the ship and the seabed using a high-frequency pulse of sound (sonar stands for SOund Navigation And Ranging). Sound travels through water at 1.48 km/s. Calculate the distance to the seabed if the...
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    Time for radio signal to get to a receiver

    Homework Statement A radio transmitter is located 17.5 km away. The broadcast signals travel at the speed of light (c = 3.00 x 108 m.s-1) through the air towards a radio receiver. Calculate the time it takes the radio signal to travel from the transmitter to the receiver. Homework Equations...
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