Fan Cart Lab

Purpose:

    In this lab we are able to understand the relationship between force, mass, and acceleration. Because of Newtons 1st, 2nd, and 3rd law and the Four Forces in Nature we are able to understand this theory better. Visual explanations of the lab could be drawn by Free Body Diagrams and Interaction Diagrams. These diagrams show us the Four Forces in Nature that are used in different kinds of situations. 

  To figure out the relationship we used a fan cart, spring, force probe, 5 different weights, and loggerpro application. This lab will also show us the difference in the velocity and acceleration of the fan cart when we put the 5 different weights.

 

Key Information: 

   First we measured the force of the fan cart without any weight on it and got F= .2338 N. Once we figured out the force we started to measure the slope of the velocity with 5 different weights. We  measured the heaviest weight first, which was 1 kg and measured the lightest weight last, which was .05 kg. In the graphs below(from left to right)it shows the force of the fan cart by itself, the slope of each trial with the different kinds of weight on it. 

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  Once we collected all of our data we began to make an equation that describes the relationship between mass, force, and acceleration.We came up with F= ma( force=mass x acceleration). We came up with this equation because we found out that the greater the mass on an object the slower it accelerates and less mass on an object means the faster it accelerates. To test if this equation is accurate, we multiplied the mass and slope to see if the result is around .2338 N, the force. Since we did add weight onto the fan cart, we had to change the mass/weight:

Key Conclusions: 

   From this lab we found out the relationship, which is F=ma. But after we finished the lab we went into a deeper understanding of this equation. Newtons 1st law is that in an object at rest or moving at constant speed will stay that way until it experiences a net force, which leads us into the 2nd law. Because of Newtons's 2nd Law, which is that forces don't cause velocity, they only cause acceleration, the net force is required to accelerate an object. The two types of diagrams help us to visually understand this. For example, in a free body diagram an object moves 130N rightward and 80N leftward. The net force magnitude is 50N and the net force direction is right because when you move 130N and 80N you are left with 50N and since the direction is positive, the direction is to the right. And finally, Newton's 3rd Law proves that 2 forces are equal, opposite, and same type(gravity, electromagnetism). 

Ex: of Newtons Laws

     

Real Life Connection:

  An example of Newtons Laws would be someone in a car when it's at rest, speeding up, moving at constant speed, and slowing down. In the drawing below we see the relationship of the acceleration and velocity. When the car is speeding up the acceleration and velocity are both positive because the car is accelerating to the right(positive) and moving right(positive). When the car is moving at constant speed the acceleration is 0 and the velocity is positive because when the car is moving at constant speed, its not accelerating but the car is still moving, which is why a=o and v= +. And when the car is slowing down, a= - and v=+ because when a car is slowing down its accelerating to the left(negative) but its still moving to the right(positive).

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.