I change the variable and an error occurs, how to fix it?

Question

Pascal

When replacing the variable grav. constant

Gmm:=6.672E-20

to the correct

6.67*exp(-11*ln(10))

, an error occurs. How to fix?

Program Gr01;

Uses GraphABC;

var x1, y1: Integer; key: boolean;
ax, ay, vx, vy, x, y, t, dt, pi, Gmm, M, r: real;
begin
  t:=0;   dt:=20;
  Gmm:=6.672E-20;   M:=5.97E24;
  x:=7000;  y:=0;   vx:=0;   vy:=10;
  Circle(320, 170, 32);
  x1:=Round(x/200); y1:=Round(y/200);
repeat 
 // setColor (0);
 Circle(320+x1, 170-y1, 2);
 r:=Sqrt(x*x+y*y);
 ax:=-Gmm*M*x/(r*r*r);
 ay:=-Gmm*M*y/(r*r*r);
 vx:=(vx+ax*dt);
 vy:=(vy+ay*dt);
 x:=x+vx*dt;
 y:=y+vy*dt;
 x1:=Round(x/200); y1:=Round(y/200);
 // setColor (2);
 Circle(320+x1,170-y1, 2);
 Sleep(5);t:=t+dt;
 until key;
 end.

Answer 1

Why don't you write the "correct" constant in a readable form (6.67E-11)?
As for the error, most likely the dimensions of the quantities used did not lead to one system. If we take a constant in the SI system, then the masses should be in kilograms, distances in meters. First, check to see if you have it.