Sunday, November 9, 2014

Vector and scalar

 scalar quantity is a one dimensional measurement of a quantity, like temperature, or weight.  A vector has more than one number associated with it.   A simple example is velocity.  It has a magnitude, called speed, as well as a direction, like North or Southwest or 10 degrees west of North.  You can have more that two numbers associated with a vector.  For example you can add a height dimension to velocity and say, for example, ' I am going uphill at a 5 degree slope in the Northeast direction'.    Vectors are frequently broken down into their components along an orthogonal coordinate system, like the x and y axes.   So you can say the y-component of my speed is 3 km/sec and the x-component of my speed is 4 km/sec.   The magnitude, or speed is the square root of the sum of the individual components, 5 in this case.  The direction with respect to the x-axis would be given by the arctangent of V/ Vx or 36.9 degrees. 
  • Time - Scalar quantities often refer to time; the measurement of years, months, weeks, days, hours, minutes, seconds, and even milliseconds.
  • Increase/Decrease in Temperature - The measurement of the medium’s temperature is a scalar quantity; the measurement of the increase or decrease in the medium’s temperature is a vector quantity.

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