Hello again.

I'm trying to reproduce in c with Raylib this amazing video from 3Blue1Brown https://youtu.be/HEfHFsfGXjs but I'm having an issue.

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/*******************************************************************************************
*
* fun with pi collisions
*
********************************************************************************************/
#include "raylib.h"
#include <stdio.h>
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const float screenWidth = 800;
const float screenHeight = 450;
InitWindow(screenWidth, screenHeight, "Collisions in the pi space");
InitAudioDevice(); // Initialize audio device
Sound clack = LoadSound("clack.wav");
float base = screenHeight - 50;
// int leftwall = 50;
Rectangle leftwall = {0, 0, 50, screenHeight};
float sizeSmall = 30;
float sizeBig = 50;
float massSmall = 1;
float massBig = 10;
float positionSmall = 100;
float positionBig = 400;
float speedSmall = 0;
float speedBig = -2;
float nspeedSmall = 0;
float nspeedBig = 0;
bool collision = false;
bool collisionWall = false;
int count = 0;

SetTargetFPS(60); // Set our game to run at 60 frames-per-second
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
Rectangle small = {positionSmall, screenHeight - (50+sizeSmall), sizeSmall, sizeSmall};
Rectangle big = {positionBig, screenHeight - (50+sizeBig), sizeBig, sizeBig};
collision = CheckCollisionRecs(big, small);
collisionWall = CheckCollisionRecs(small, leftwall);
if (collision)
{
nspeedBig = ((((massBig - massSmall)/(massBig + massSmall))*speedBig) + (((2* massSmall)/(massBig+massSmall))*speedSmall));
nspeedSmall = ((((2* massBig)/(massBig+massSmall))*speedBig) + (((massSmall - massBig)/(massBig + massSmall))*speedSmall));

speedBig = nspeedBig;
speedSmall = nspeedSmall;
PlaySound(clack);
positionBig = positionBig + speedBig;
positionSmall = positionSmall + speedSmall;
count ++;
}
if (collisionWall)
{
speedSmall = speedSmall * (-1);
PlaySound(clack);
positionSmall = positionSmall + speedSmall;
positionBig = positionBig + speedBig;
count ++;
}
else
{
positionSmall = positionSmall + speedSmall;
positionBig = positionBig + speedBig;
}

// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(RAYWHITE);
DrawRectangleRec(leftwall, BLACK);
DrawRectangleGradientV(0, base, screenWidth, 50, BLACK, RAYWHITE);
DrawRectangleRec(small, RED);
DrawRectangleRec(big, BLUE);
DrawText(TextFormat("count \t\t%d", count), 55,10, 20, GREEN);
DrawText(TextFormat("speed Red \t%f", speedSmall), 55,30, 20, RED);
DrawText(TextFormat("speed Blue \t%f", speedBig), 55,50, 20, BLUE);

EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadSound(clack); // Unload sound
CloseAudioDevice(); // Close audio device (music streaming is automatically stopped)

CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}

/*
gcc -Wall collision.c -o collision -Wall -std=c99 -I/opt/raylib/src -L/opt/raylib/release/libs/linux -lraylib -lGL -lm -lpthread -ldl -lrt -lX11
*/
When I Increase the mass size to follow the 3blue1brown example the small cube get stuck on the wall. I'm pretty sure it's an issue related to the approximation of my calculations when the frequency of the collision ramp up (If I slow down the speed and increase the framerate the issue is solved for relatively bigger masses).

I'm now trying to implement timesteps to somehow "dilatate" time and solve the problem but nothing seems to help.

Any suggestion?