Equations for detecting collision

[kachilous]

I have created a program that simulates an object being thrown off a 50 m building.
Now I would like to implement collision detection. What equations would I need to accomplish this? I am taking Physics right now, so my Physics is a little rusty.

I know I will have to find the time of collision:
timeImpact = (-vy - sqrt((vy*vy) - (2*ay*y)) / (2*.5*ay))

Will I also have to find the object's velocity and position at impact too?

I also decided that the object's coefficient of restitution will be .5.
So I know I will have to factor that in as well.

Any help would be appreciated.

 

[DickL]

You will need the position (y) of the object. When the position of the object is equal to the altitude of the ground (y=0) its collided. In order to analyze the post collision dynamics you will probably also want the time and velocity. If your approach is a time step analysis, it is quite easy to also compute the time, position, velocity, acceleration in a time step table format.

 

[kachilous]

What do you mean by time step analysis?

 

[DickL]

A time step analysis uses a constant increment of time, say 0.1 sec, and computes the necessary data (total time, position, velocity, acceleration) for each step in time. Then uses those results to compute the next increment.