Hover Disc and Fan Cart Lab

The purpose of this lab was to understand Newtons three laws of motion. By using hover discs and carts powered by fans, we were able to derive equations relating force, mass and acceleration (change in velocity/change in time). The leading questions for the lab were: 

1. What gives rise to a change in motion? (Hover Disc Lab)
2. What is the relationship between mass, force and acceleration? (Fan Cart Lab)

Important Info + Lab Summary:

Hover Disc Lab: Using soccer ball hover discs, we performed the lab by experimenting with different types of force acting on the disc and its surroundings. The most popular forces during the lab were: normal force (Fn) and gravitational force (Fg). Normal force acts up an object when the electrons on the surface of the atoms repel, and gravitational force is present when two objects that have mass are going in the direction the most massive object. 

Key Data:
To represent forces acting upon an object in a diagram, there are two different forms:

- Interactive Diagrams:

1. Draw all objects present (don't forget the earth!)
2. Draw lines to connect objects that are interacting
3. Label each line with the type of force

- Free Body Diagram:

1. Draw a circle representing a single object
2. Draw arrows from the circle to represent direction, type of force and magnitude
3. Make sure that the length of the arrows reflect the amount of force acting on the object

"For every action, there is an equal and opposite re-action."

Important Info + Lab Summary:

Fan Cart Lab: We began the lab by attaching a fan to a cart (.3 kg) and applying a constant force. During the lab, we added different amounts of brass masses to the fan cart and placed it back on the metal track where the sonic range finders and force probe were. Using the Loggerpro on the computers, we were able to calculate the acceleration of the cart. 

Key Data: 

- There is an indirect relationship between mass & acceleration

-  NEW EQ: force = (mass)(acceleration)

- An object will accelerate in the direction of the net force

- Objects at a constant motion will remain constant unless an outside force acts upon it

Real World Connection: When a bug collides on the windshield of a car, both will experience the same amount of force. Even though the less massive bug dies, it is just because the truck is so much more massive that it experiences a smaller acceleration. 

Impulse Lab

The purpose of this lab was to identify the relationship between impulse, force and time during a collision. Beginning the lab, we defined what impulse actually was. We came to the conclusion that impulse is a change of momentum or the conservation of momentum in a collision. 

Important Info and Lab Summary: To find the relationship between impulse, force and time, we conducted an experiment using a red car, a metal track, range finders on either side of the track and metal bands attached to the cars and the end of the track. The metal bands were used to slow down the collision time. Sending the analysis from the range finders to the computers, we were able to see the entire journey of the car - before, during and after the collision. We pushed the red car towards the left of the track ( - sign ) and it immediately bounced back, it was an elastic collision. We then used the graph on the computer to extract the mean and integral of the red car. 

Key Data: 
- Impulse = momentum final - momentum initial (Pf-Pi)
- Impulse equation: J=F (force) X T (time)
- Impulse is a constant on an object in a collision
- Impulse = area of force vs. times graph
- Force and time are inversely proportional

Real World Connection: A bullet proof vest is something that is critical for all policemen and women to wear. The vest has the ability to protect the person from a severe bullet wound and slow down the momentum of the bullet from projecting further at the time of collision. The vest creates an impulse which allows the bullet to take more time before reaching the Cop, decreasing the force or impact they would feel. 

Collisions Lab

The purpose of this lab was to develop our understanding of momentum and the amount of energy stored in both an elastic vs. inelastic collision. The big question being: Is energy or momentum better conserved in a collision?

Important Info and Lab Summary: To simulate a collision, we used a red and blue cart and placed them on a straight metal track. Using range finders on both sides, we collected their velocity or speed throughout the entire collision (before and after). To perform an elastic collision we arranged the carts so that their springs stuck out in front of each other, we then pushed them into each other for a collision. The result being that they bounced off but went in the same direction (left). The red cart started motionless (at rest) while the blue car was pushed towards it, once they hit then the collision occurred. My group noticed that a transfer of momentum was taking place. The red car, which began with no velocity, was in in motion after the collision - meaning that momentum must have been transferred from the blue cart to the red. The second step was to perform and inelastic collision.  We pushed the red cart towards the blue cart (was still) and they almost immediately attached together (Velcro force b/w them) and continued to travel in the same direction (left).

Key Data:

- p=mv (momentum = mass X velocity)

- Energy loss in inelastic > Energy loss in elastic ** both cars are absorbing the energy

- In elastic collisions cars store more energy in kinetic form

Real World Connection: All golf is is collisions! The energy from a club is transferred to a ball that is at rest prior to the hit.

Rubber Band Car Launcher Lab

The purpose of this lab was to discover the relationship between velocity, mass and energy. In our experiment we used an air track, red launcher "cart" and a rubber band. In order to introduce potential energy into the experiment, we had to pull the cart towards us (towards rubber band), and then release the cart which would then travel in a forward motion.

Important Info and Lab Summary: As the cart moved away from the rubber band, we realized that kinetic energy was being transferred due to the fact that the cart was in motion. It became clear that as we stored more energy in the rubber band, more speed/velocity was the product. In conclusion, we figured out that energy and velocity contain a direct relationship. The more energy stored in the rubber band, the further and faster the cart will move when that energy is released. The proof to our consensus was in the data we took from launching the cart from 1-5 cm of the stretched rubber band.

Key Data:
- K = kinetic energy (energy in motion)
- K=1/2 mass X v^2
-Ug = gravitational potential energy (effect of gravity on downward pull of object when lifted at a certain height
- mg = mass X acceleration due to gravitational pull
- h = height of lift
- Ug = mgh

Real World Connection: A fun toy for the upcoming car-obssessors, when winding back the Hot Wheels, the spring inside becomes fully loaded. This allows the car to accelerate (energy transfers to kinetic) and charge ahead without having to be pushed.

Rubber Band Lab

Important Info + Lab Summary: We began the lab using an electronic force probe attached to a single looped rubber band. We then stretched it 1cm, 2 cm, etc. until we reached 5 cm. We did this twice in order to get the most accurate data. After our second trial, we continued doing the same experiment but increased the number of loops from one to two. 

The purpose of this lab was to understand the relationship between force, distance and stored energy. We were to discover how we can store energy to do work for us later and analyze how much force it takes to stretch a rubber band depending on the distance in which it is stretched.







Key Data:

- Best line graph = y=mx+b
- I.V = distance stretched
- D.V = Force (N)
- Slope of best fit line = y=110x
- Fs=kx (elastic constant - force needed to stretch/distance stretched)
- 110 = k, the constant

Conclusion to Lab: In order to calculate how much energy was stored in the rubber band, we had to come up with an equation. In this specific scenario, the equation we came up with was Us (elastic potential energy) = 1/2 (b)(h) - the area (b) times (h) divided by two. The product of (b)(h) then represents Fs (force needed to stretch N) which = K(elastic constant) x X (distance stretched). Our equation is finally simplified to: Us = 1/2 k times x^2

Relationship to Real World: As you jump up and down on a trampoline, the "elastic like" material allows for enough energy to be stored so that while you keep jumping, it is able to jolt your body up further and further.

Pyramid Lab

The purpose of this lab was to recap on all of the standards we learned, including 2.1, 3.1, and 3.2. We were to recognize the relationship between force and distance and then find out if force and distance were actually universally conserved. We used a ramp, force probe, toy car and a simple machine to conduct this lab. 

Important Information and Lab Summary: That data that we recorded proved that force and distance are inversely related to one another, meaning as one increases the other decreases. In this case, as distance increases, force decreases and vice versa. Through this data we are able to conclude that the product of force and distance are universally conserved. It did not matter how fast we were moving the car up the ramp, the same amount of work (energy) was used each time. 

Key Data: 
- W=fd
- work and energy are always conserved
- work is being done when an object is being moved (energy)
- energy = the ability to do work 

Real World Connection: Ramps are props in many different X game sporting events, involving skateboarding and BMX riders to name two. When the ramps are longer and the degree of the ramp is less sharp, it does not cause the skaters to need that much force in order to reach the other side. But when a ramp is shorter and more angular, the skaters need to put in much more force into this shorter amount of distance, even though energy turns out to be conserved. 

Pulley Lab

The Purpose of this lab was to understand how force can be manipulated by simple tools and machinery, like a pulley. The goal of the lab was to use the pulley machine, string, a manual force probe, and a brass object (mass of 200g) to distinguish the relationship between force and distance while using a simple machine, in this case a pulley.


Important Information and Lab Summary: By using simple machines like a pulley, we are able to decrease the amount of force needed to lift weight, in this case a 200g brass mass. But like most things, there is always a catch or a trade off - in order to minimize the force exerted, we must increase the distance used. In the lab, decreasing the amount of force meant applying more string.


Key Data/Points:

- Increase distance = decrease in force (vice versa)
- Without a pulley: 200g = 2 N of force
- With a pulley: 200g = 0.9 N of force w/20 cm of string (distance)
- Area is equal to force times distance
- Energy transferred by applying a force over a distance = Work (J)
- W = Fd

Connection to real world:                                                                               

In most theaters, the stage crew uses an actual
pulley to lift and lower the curtain. By using the pulley, it allows the stage crew to lift the heavy curtain more easily and requires less effort to lift it. The pulley allows for a large amount of mass to be lifted with a little amount of force required as well as being a lot more convenient than doing it manually.

Mass VS. Force Lab

The purpose of this lab was to correlate the relationship between the mass (m) and force (F) of an object. Through the use of a manual force probe and an electrical one, we were able to collect data and produce graphs that show how many newtons (N) of force were needed for the various masses (kg). During this lab, we also learned more about the scientific usage of a best fit line.

Important Info and Lab Summary: When trying to find the amount of force (F) needed for the various brass masses, we had to use a force probe - both manual and electronic. From the probe, we were able to hang each mass and measure the amount of force in newtons (N) that were exerted on it. One of the most challenging part of the labs was keeping the electric force probe steady, making the results as accurate as possible.

Key Data: 
- Mass of object (independent variable) lays on the x-axis
- Force (dependent variable) lays on the y-axis
- Once graphed we found the slope of the line (slope = 10 N/kg)
- By using the slope we were able to figure out the equation F=mg
- F=mg provides us with a constant equation to calculate the force of gravity on earth which turns out to be about 10 times the mass (kg) of an object

Relationship to the real world:
This lab is super easy for us to see in our own lives. Through this activity I have learned that with an increase of mass, there is also an increase of force being exerted on that mass object. This law of the more mass the more force needed, is present in our lives when exercising. When lifting weights for example, a 5 pound weight is much easier to lift than a 25 pound weight. This is because the gravitational pull is stronger on the 25 pound weight than it is on the 5 pound weight due to the fact that less mass is present, and less force is needed!

This may be harder than...

THIS!