Impulse Lab

Purpose:
 The purpose of this lab is to understand the relationship between impulse, force, and time during a collision. Knowing this can help strengthen our knowledge more about what happens during a collision and after the collision. Impulse is about the change in momentum after a collision whether its change is negative or positive when force and time is applied. To test this we used a force probe with a spring, a cart with a spring on a ramp, and an application called LoggerPro to graph our collision.

 Key Information:
   First, it is important to understand what is an impulse( J= deltaP=Pafter-Pbefore). Impulse is the change in momentum when objects are involved in a collision and in order for this to happen we need to apply a force over time. These objects experience equal and opposite impulse because momentum is conserved.
                   

   In this lab we started out by pushing the blue cart towards the force probe. Then with the graph we were able to record the velocity before of the blue cart, velocity after of the blue cart, and the area of force vs. time. Afterwards we were able to find the impulse of the collision= -.16. With all this information we are able to find the percent difference-- impulse - area of F x t/ impulse + area/2 X 100.

Key Conclusions:
  From what we've recorded we discovered that the relationship between impulse, force, and time is equal to each other--> J= F x t, the change in momentum is equal to the area of force-time.In other words the impulse of before and after a collision is equal but opposite. For example, we have a blue cart and a red cart involved in a collision. From there we have calculated the impulse and recorded force and time. Then we would have:

Jred= -Jblue        Jred= -Jblue
t red= t blue        deltaPred= -deltaPblue
Fred= -Fblue       delta(MredVred)= -delta(MblueVblue)
                        less mass=more velocity            more mass=less velocity

Real Life Connection:
 An example of an impulse collision would be a bullet proof vest because when someone gets shot at wearing this it prevents them from actually getting hit from the bullet. A bullet is an applied force over time and when it hits the bullet proof vest it creates an impulse( causing a change in momentum), slowing down the time when its suppose to actually hit the person's chest.