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Why anticlockwise direction is taken as positive?

Why in Mathematics and physics every object is taken in anticlockwise sense called as positive sense? Generally in our day to day life we use clockwise direction to go round a temple or something like that. Also our wall clock will go round from left to right.?


Sadhakshi Devi asked




Normally we take the positive X axis as reference. When moving UP (positive) the movement is in the anticlockwise direction. This is the logic behind taking anticlockwise as positive and clockwise as negative.


Measuring from the x-axis, angles on the unit ...


Calculating velocity of an approaching vehicle

Is it possible to design a device that calculates the velocity of an approaching vehicle if the speed of sound in air at that location  is known?


Asked Vibhava




Now the source is moving at the speed of sound...


Such a device is already in use. It is based on a phenomenon called Doppler Effect.


Get the details at the following Links.


  1. www.physicsclassroom.com/class/waves/u10l3d.cfm
  2. science.howstuffworks.com/science-vs-myth/everyday-myths/doppler-effect3.htm
  3. http://en.wikipedia.org/wiki/Doppler_effect



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