Answer Modulus of Speed: Calculation w/fluid mech.

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The modulus of speed (u) in fluid mechanics is calculated using the equation u = (-2/r)e_r + (2/r)e_theta. The terms e_r and e_theta represent unit vectors in the radial and angular directions, respectively, indicating directionality in plane polar coordinates. The user is uncertain about the impact of these unit vectors on the calculation and proposes that the answer is square root 8/r. Verification of this calculation is sought from others in the discussion. Understanding the role of e_r and e_theta is crucial for accurate modulus of speed calculations.
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Homework Statement


i just want to know what the modulus of the speed (u) would if


Homework Equations


u = (-2/r)er + (2/r)etheta

The thing is i get confused with the er and etheta ..do these just mean the direction...this topic is fluid mechanics

The Attempt at a Solution


i reckon the answer is square root 8/r ...as i reckon the e's don't get affect...can some one verify this

 
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The e_r and e_theta are directions in plane polar coordinates.
 

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