Question: how do i change parameters

This is what i have done to find the difference between a ball thrown with different starting angle, and then ploted they into the same plot.

restart; Digits:=20: with(plots):

C_0:=0.4: d:=0.0002: mu:=1.8*10^(-5): rho:=1.2: g:= 9.81:
rho_v:=1000.0: m:=evalf((4/3)*Pi*rho_v*(d/2)^3):   


F_D:=proc(v::list)                 
local k,vx,vy; 
vx:=v[1]; 
vy:=v[2]; 
k:=-evalf((3*Pi*mu*d+(Pi/8)*C_0*rho*(d^2)*sqrt(vx^2+vy^2))/m);      
[k*vx,k*vy];                                                      

Eskritt:=proc(vo::list,h)  
local vx,vy, F;  F:=F_D(vo); 
vx:=vo[1]+h*F[1]; 
vy:=vo[2]+h*(F[2]-g);  
[vx,vy];  
end proc;

v_0:=1.0:  phi:=Pi/4:  v0:=evalf([v_0*cos(phi), v_0*sin(phi)]): v[0]:=v0;       # Pi/4=45 grader
h:=0.002: N:=65:

for i from 1 to N do  
v[i]:=Eskritt(v[i-1],h);
end do:
r[0]:=[0,0]:
for i from 1 to N do  
r[i]:=r[i-1]+h*v[i-1];
end do:
p1:=plot([[r[j] $j=0..N]],scaling=CONSTRAINED, color = green): 

phi:=Pi/5: v0:=evalf([v_0*cos(phi), v_0*sin(phi)]): v[0]:=v0;      # Pi/5=36 grader
h:=0.002: N:=55:

for i from 1 to N do  
v[i]:=Eskritt(v[i-1],h);
end do:
r[0]:=[0,0]:
for i from 1 to N do  
r[i]:=r[i-1]+h*v[i-1];
end do:
p2:=plot([[r[j] $j=0..N]],scaling=CONSTRAINED, color = red): 

phi:=Pi/6: v0:=evalf([v_0*cos(phi), v_0*sin(phi)]): v[0]:=v0;      # Pi/6=30 grader
h:=0.002: N:=50:
for i from 1 to N do  
v[i]:=Eskritt(v[i-1],h);
end do:r[0]:=[0,0]:
for i from 1 to N do  
r[i]:=r[i-1]+h*v[i-1];
end do:
p3:=plot([[r[j] $j=0..N]],scaling=CONSTRAINED, color = blue):

display({p1,p2,p3}, labels=["",""]);

I now want to change the parameters of (mu rho and g) and create a new plot with those 3 plots in one, but i cant find a solutions. Do any one know what to do here?