Help Finding path of a particle with an intial position and initial velocity

[ezedvin1]

Hi everyone,

I am having trouble finding the answer to a homework problem. I don't seem to understand what the question is exactly asking for. The problem is:

find the path of a particle with an initial position 10e_r + 1.0e_ϴ and an initial velocity 0.1e_r + 0.8e_ϴ

 

[ppfn]

Have you considered using the kinematics for cylindrical coordinates?

 

[ezedvin1]

the equations I am thinking about using are

Cylindrical coordinates: r, ∅, z
x=rcos∅ y=rsin∅

Spherical Coordinates: r, θ, ∅
x=rsinθcos∅ y=rsinθsin∅ z=rcosθ

I also know an equation for velocity as v=\dot{r}e_r + r\dot{θ}e_θ

I'm still very confused as to what to do with all these equations to find the path of the particle. Please Help.

 

[ppfn]

Those equations look like they are for converting from Cartesian coordinates to cylindrical / spherical coordinates.

Try looking around in your book for the kinematic equations in cylindrical / spherical form. If they aren't in your book you could try going to this link

en.wikipedia.org/wiki/Equations_of_motion

and try looking for them by Crtl+F and typing in what you're looking for.

I haven't ever worked with those coordinate systems and kinematic equations before, otherwise I would be more helpful.