Homework Help: Changing from cartesian to polar

1. Sep 15, 2008

CompStang

1. The problem statement, all variables and given/known data
A particle moves in a two-dimensional orbit defined by:
x(t)= A(2$$\alpha$$t-sin($$\alpha$$t)
y(t)= A(1-cos($$\alpha$$t)
a) Find the tangential acceleration a_t and normal acceleration a_n as a function of time where the tangential and normal components are taken with respect to the velocity.

2. Relevant equations
x''(t)= A$$\alpha$$^2sin($$\alpha$$t)
y''(t)= A$$\alpha$$^2cos($$\alpha$$t)

3. The attempt at a solution
I found both the velocity and acceleration for both x and y vectors given and realize that a(t)= x''(t)i$$\widehat{}$$+ y''(t)j$$\widehat{}$$
also I know that:
a(t)=a_nr$$\widehat{}$$+a_t$$\phi$$$$\widehat{}$$
So I need to find x" and y" in terms of polar to get the answe for a_n and a_t

2. Sep 15, 2008

CompStang

sorry all these alphas are not supposed to be raised to the power of there previous components. it is supposed to be for example x(t)=A(2*(alpha)*t-sin((alpha)*t).....and so on