Southerly Deflection by Motion of the Earth

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SUMMARY

The discussion focuses on calculating the southerly deflection of a particle falling in Earth's gravitational field, as outlined in Chapter 11, Problem 13 of "Classical Dynamics of Particles and Systems" (5th ed.) by Marion and Thornton. The calculation employs the zeroth order time-of-fall equation, T = √(2h/g), and incorporates second-order approximations for the Coriolis force, centrifugal force, and gravitational force. The results for the three components are given as C1 = 2/3, C2 = 5/6, and C3 = 5/2, leading to a formula for deflection that includes terms in ω².

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  • Understanding of classical mechanics principles, particularly dynamics.
  • Familiarity with the Coriolis effect and its mathematical representation.
  • Knowledge of gravitational force calculations, specifically using Newton's law of gravitation.
  • Ability to perform calculations involving Taylor series expansions for approximations.
NEXT STEPS
  • Study the Coriolis force in detail, focusing on its application in rotating reference frames.
  • Learn about centrifugal force variations with height and their implications in dynamics.
  • Explore gravitational force variations with height, particularly in the context of Earth's radius and altitude.
  • Investigate advanced topics in classical mechanics, such as perturbation theory and its applications in dynamics.
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Students and professionals in physics, particularly those studying classical mechanics, as well as engineers and researchers interested in the effects of Earth's rotation on falling objects.

bob1182006
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Marion and Thornton Classical Dynamics of Particles and Systems 5th ed. Chapter 11 #13.

Homework Statement


(Refers to an example where they calculated the horizontal deflection from the plumb line of a particle falling in Earth's gravitational field).
Take g to be defined at ground level and use the zeroth order result for the time-of-fall, T=\sqrt{2h/g}. Perform a calculation in second approximation (retain terms in w^2) and calculate the southerly deflection.
There are three components to consider (a) Coriolis force to second order (C1), (b)variation of centrifulgal force with height (C2), (c) variation of gravitational force with height (C3).

Each component gives a result:
C_i\frac{h^2}{g}\omega^2sin(\lambda)cos(\lambda)
with C1=2/3, C2=5/6, C3=5/2.


Homework Equations


\vec{F}=\vec{S}+m(\vec{g_o}-\vec{\omega}\times(\vec{\omega}\times\vec{r}))-2m\vec{\omega}\times\vec{v_r}
\vec{g_o}=-G\frac{M_e}{(R_e+h)^2}

The Attempt at a Solution


The coordinate system has z radially outward from the Earth. x in the southerly direction, y in the easterly direction.
\lambda is the latitude.
\vec{S}=0, Assuming no external forces like air resistance.

\vec{\omega}=-\omega cos\lambda\vec{e_x}+\omega sin\lambda\vec{e_z}
R_e+h is in the positive z direction
\vec{\omega}\times(\vec{R_e}+\vec{h}})=(R_e+h)\omega cos\lambda \vec{e_y}
\vec{\omega}\times(\vec{\omega}\times(\vec{R_e}+\vec{h}))=-\omega^2(R_e+h)sin\lambda cos\lambda \vec{e_x}-\omega^2(R_e+h)cos^2\lambda \vec{e_z}

For v_r I think it should be just -gt in the radial direction. But my book says that the Coriolis Force produces a small velocity component in the y and z directions that they neglected.
Would the component of the velocity of the z direction be -g_ot-t\omega^2(R_e+h)cos^2\lambda? Or is it just -gt?
 
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I believe your problem asks for only terms up to \omega^2. So you can treat the velocity as -gt in the z-direction. But you might want to check this.
 

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