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26 Nov 2019

Dipole oscillations

To understand the motion of a diatomic molecule in a uniformelectric field, let us consider a dumbbell model where the moleculeis made of two point particles with identical mass m = 9 × 10-27 kgand charges +Q and -Q (Q = 2 µC). These particles are separated adistance d = 4 µm from each other. The molecule is in a region ofspace with a uniform electric field of magnitude 300 N/C.Initially, the electric moment of the molecule makes an angle of 5°with the electric field. The molecule is released from rest.

(a) Find the magnitude of the initial torque on the molecule.

t = ??? N m

(b) Find the kinetic energy of the system as it passes through theequilibrium position.

KE = ??? J

(c) Since the answer to (b) is not zero, the molecule will keepmoving past the equilibrium position, reach an angle of 5° on theopposite side and rotate in the opposite direction. Therefore theresulting motion is an oscillation about the equilibrium position.Find the frequency this oscillation.

f = ??? Hz

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Jarrod Robel
Jarrod RobelLv2
11 Nov 2019

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Related textbook solutions

Physics: Principles with Applications
7th Edition, 2013
Giancoli
ISBN: 9780321625922

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