Alternating acceleration understanding ?

  • Thread starter Thread starter khurram usman
  • Start date Start date
  • Tags Tags
    Acceleration
AI Thread Summary
Alternating current (AC) operates by reversing direction periodically, allowing energy to be transferred without a net flow of electrons, unlike direct current (DC). This concept can be visualized as a progressive wave, where energy moves from one maximum to another, with the direction changing at specific intervals. AC appliances, such as light bulbs, do not flicker noticeably to the human eye despite alternating at frequencies like 60Hz or 120Hz, as the flicker occurs too rapidly to be perceived. The changing magnitude of AC does not cause significant fluctuations in brightness for most appliances because they are designed to handle the variations in voltage and current. Understanding these principles clarifies how AC can efficiently deliver energy to homes without the drawbacks of DC.
khurram usman
Messages
86
Reaction score
0
alternating acceleration understanding...?

i have a basic understanding of this topic...i understand this thing when it is explained using a closed rectangular circuit in books...it is easy to imagine that in a small closed circuit the current first flows in one direction then in the other.
but i could not understand how can alternating current reach our homes ...i mean first we say that in one direction and after half a time period it moves in the other...so in a sense it should reach back its starting point...kindly explain this and improve my understanding
someone told me to view this as a progressive wave/transfer of energy...where energy goes from one maximum to other maximum...but what i don't uinderstand is how and when it changes it direction?
secondly i remeber someone telling me that a AC bulb blinks about 60 times in a minute...but obviously our eye can't detect that...now if i assume that progressive wave concept which i don't clealy undrstand how is this explained?
thirdly the alternating voltage will cause the current to alternate ...that is its direction and magnitude both change(since its a sine wave)then doesn't this magnitude changing affect the appliances...i mean why don't tube lights and bulbs glow sometimes brightly and sometimes dimly?
please provide me an explanation and a physical interpretation of these concepts
 
Physics news on Phys.org


Think of it like this, me pushing a rod(electrons) into you to supply you with energy (DC), or me pushing and pulling the rod(electrons) to and from you (AC). While I would run out of rod(electrons) eventually by only pushing it to you(DC), this would not happen if I pushed it and pulled it(AC). Instead, I just have to provide the energy in pushing and pulling, and not a supply of electrons. It is the potential in the circuit which is usable energy, and alternating that potential allows you to do work, without having any 'net' flow of electrons.

And yes things like light fixtures running off AC flicker at a frequency of either 60hz or 120hz, i forget which. Its too fast for our eyes to detect, but when you record an old school monitor with an older camera, you will see that it is flickering and doing strange things that we don't notice.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
Back
Top