Step-by-step explanation:
Step1
Any physical, chemical or mechanical quality which is defined with respect to the change in position is called gradient of that quantity. Velocity gradient is the rate of change of velocity with respect to position.
Step2
Gradient of any physical quantity depends upon position. So, that physical quality is not uniform with respect to position. For example fluid pressure changes position to position. So, the gradient of pressure is defined as the rate of change of pressure with respect to position.
Step3
Expression for velocity gradient is expressed as
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