# Collision in physics

This topic is 2083 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

I began testing the physics I learned in school about 7 months ago or so. Once I started I realized that... I forgot it all lol. To test my physics i basically made 3 rectangles move in random directions and acceleration is CONSTANTLY increasing on each of them.

the collision is basically what I'm working on.

ive looked all over google but i can't find anything that really helps me, or at least i don't understand most of it.

in my object class i have
 Rect rect; // The rectangle I am drawing and checking collision with Vector2 pos; Vector2 velocity; Vector2 acceleration; Vector2 momentum; // I can't remember if this is supposed to be a vector or a number lol float mass; // I know how to calculate the momentum momentum = mass * velocity; void CheckCollision(Object *Other) { float dt = time.GetDeltaTime(); RECT colRect; // Check for a collision if(IntersectRect(&colRect,&rect,&Other->rect)) { // There was a collision, now lets do physics // Calculate the force first? And im not sure if I'm doing this correctly, cause you can't multiply a vector by another vector Vector2 myForce = mass * momentum * velocity; Vector2 otherForce = Other->mass * Other->momentum * Other->velocity; // I'm not sure if i know how to calculate the impulse either, this is from what I remember + what I gathered online that i couldn't really understand Vector2 impulse = myForce-otherForce * dt; } } // I just want to do the collision with physics without anything else involved like: Friction,Gravity, Air Resistance or what have you. // Do I need to use the Coefficient of Restitution? and if so what exactly is that and how do I calculate it? 

##### Share on other sites
Have you read my article 'physics engines for dummies' where I cover the basics of a physics engine?

http://www.wildbunny.co.uk/blog/2011/04/06/physics-engines-for-dummies/

Cheers, Paul.