# Question:How do i switch between time and angle?

## Question:How do i switch between time and angle?

Hey there,

i have an System in the form below.

I try to plot s over the angle t which is used in the functions (S,DS and DDS) but because maple uses t in the functions (s, v and a) as the time the calculated eigenfrequency doesnt fit to the System.

The eigenfrequency should be omega:=sqrt(c[0]/m[1])=1035 (over 360 degrees) but because of the angle time switch the eigefrequency is 1035 (over 1).

Has someone an idea how i can tell maple that t is an angle in degree? ( It is necessary to plot s over the angle in degree)?

T := module() option package;
export sin, cos;
sin := proc(x) :-sin(x*Pi/180); end proc:
cos := proc(x) :-cos(x*Pi/180); end proc:
end module:

S:= sin(t):

DS:=diff(DS,t):

DDS:=diff(DS,t):

s := proc (t) options operator, arrow; x(t) end proc;
v := proc (t) options operator, arrow; (D(s))(t) end proc;
a := proc (t) options operator, arrow; (D(v))(t) end proc;

m[1] := 42:

c[0]:=45000000:

d[0]:=10:

ODE := m[1]*a(t)+d[0]*v(t)+c[0]*s(t)= -(1/1000)*c[0]*S-(1/1000)*d[0]*DS*(2*(250*(1/60))*Pi)-(1/1000)*m[1]*DDS*(2*(250*(1/60))*Pi)^2;

﻿