[Phys-L] Re: notation for initial velocity components

[mungan at USNA.EDU (Carl Mungan)]

> | I agree with Michael's notation and the reason I like F_12 is
> | because I think of the 2nd subscript as a semi-optional
> | sub-subscript: hence
> | F_1 = sum over i of F_1_i. (Optional because if there are
> | only two objects of interest then the net force on 1, F_1, is
> | the force on 1 due to 2, F_1_2. The subscript 2 is then only
> | a reminder, which we can drop when we get tired of writing it.) -Carl
>
> OTOH, the subscript, particularly in a FBD, usually refers to the object
> causing the force, not the object receiving the force.
>
> E.g.  F_s for spring force acting on an object, or F_T for the tension
> in a rope acting on an object, etc.

Good point. So if there are several springs and masses (like in a
coupled oscillator problem), we may need to write things like F_1_s_2
for the force on mass 1 due to spring 2, right? :-) Carl

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Carl E. Mungan, Asst Prof of Physics  410-293-6680 (O) -3729 (F)
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