Newton's Three Laws

                                            Design:        
                                           

Through the fan cart lab and hover disc lab that we did in our physics groups, we demonstrated and analyzed Newton's three laws of motion. In the hover disc lab, a device with a small fan at the bottom was used. This device could gravitate a few inches above the ground, counteracting friction. We described the relationships and natural forces that occur among the device, Earth, and two people who provided an outside net force. Interaction and free body diagrams can be used to map out the forces at work within this system. During the fan cart lab, we measured the amount of force a fan cart would project onto a sensor. We increased the amount of mass on the cart for every new trial as the distance and fan pressure remained constant.

                             Reflection:

The fan cart lab and hover disc lab satisfies Newton's first law. (which states that an object moving at a constant speed will stay that way unless it experiences a net force) The fan, which eventually attained a constant speed could, theoretically, never stop or slow down unless it experiences a net force. The net force in this case was a person's hand or the electronic probe. The hover disc, when pushed, could maintain a constant speed because of its ability to gravitate above the ground and counteract friction.
                  Both labs also describe the Second Law. (a net force will accelerate an object) The fan attached to the cart provided a steady force by which the cart could move. When the fan pressure was increased or if someone applied their hand to the cart, it would experience acceleration. The harder the force that was applied on the hover disc, the faster it would propel forward and the faster it would accelerate if it had already been moving.
                  The fan cart and hover disc labs illustrate Newton's third and final law of motion (for every action, there is an equal and opposite reaction). When the cart was forced against the sensor, it nearly bounced back to the same position that it started at. Some energy was lost as heat on the track. When a person pushes the disc against a wall, the harder they push the disc, the greater the distance of the recoil.

       
          Real-World Connection:

In regards to Newton's Third Law, a person discharging a firearm is a prime example. Guns with greater firepower produce much greater recoil and apply an equal and opposite force back to the shooter. A shotgun produces much greater recoil than a pistol.





Fun Fact: Newton first published his work, which included his three laws of motion, in the book Philosophiae Naturalis Principia Mathematica on July 5, 1687.

Impulse Lab

Big Question: What is the relationship between impulse, force, and time during a collision?

                                                                       Design:

In this lab, the necessary materials were a force-probe ring stand, one sonic range finder, a red cart, and a track slide. The empty red cart was thrown towards the force-probe attached to the ring stand. The cart collided with the force probe. Then, the sonic range finder measured the data and, using the LabQuest device, put it into s Force vs. Time graph. Our group also recorded the cart's velocity before and after the collision.

                                                                      Reflection:

The data found in our experiment was calculated with the equation for Impulse (J=Pafter-Pbefore). P is the symbol for the momentum (Mass xVelocity). As usual, human error and technical difficulties played a small role in the experiment and has a slight effect on the data. We concurred that greater time minimized the impact of a force. The above diagram illustrates the interwoven relationship between impulse, force, and time.

                                                       


                         Real-World Connection:

A bat hitting a ball is an appropriate real-life example of impulse. This is a change of momentum, and momentum is mass times velocity, so any real-life situation where there's a change of velocity (acceleration) there's an impulse.

Collisions Lab

 Big Questions of Experiment:

"What is the difference between the amount of energy lost in an Elastic Collision vs. Inelastic Collision?"

"What is a better conserved quantity- momentum or energy?"

                                                                Design:

This lab involved the examination of three different types of collisions: elastic, inelastic, and explosions.The necessary tools utilized for this endeavor included the LabQuest device, two sensors, two 250g carts with velcro and a spring launcher, and a track. For the elastic collision, the two carts were sent towards one another with the spring launcher bearing the brunt of it, and causing the carts to bounce off. Next, the inelastic involved a similar process yet the velcro was used, so that both carts would stick together. Finally, for the explosion, both carts were originally attached by the velcro and then violently separated as the spring launcher was activated. The sensors detected the force at different points of the collision and sent the data to the LabQuest. We recorded the data from the device to our iPads using the collision sheet template.  

              Reflection:                                                           

To help analyze the data, two formulas were used, P=mv to calculate momentum and KE=1/2mv^2 for kinetic energy. Through our calculations, it was determined that momentum is a better conserved quantity and that, overall, conservation of energy occurs more in an elastic explosion compared to inelastic. Human error, as always remained a factor, yet technical difficulties were minimized due in part to greater experience with the equipment. 

                                                      

                                     Real-World Connection:

A collision between two cars can be best described as an inelastic collision. If an accident is severe enough, the two cars come together as one pile of wreckage.

                                                                                                                   

A video that puts into simple terms the difference between elastic and inelastic collisions.

Rubber Band Cart Launcher

                                                                     Design:

The "Rubber Band Cart Launcher" experiment was conducted with an electronic force probe, a Photo gate velocity timer, red air glider, an air track, and a rubber band. The red air glider was pushed against a rubber band (at varying lengths between 0.01 meters and 0.05 meters). When the glider was released it moved down the air track and its velocity was detected by the photogate device. The air track's plane remained at a neutral incline. Two trials were conducted in order to identify and minimize human error. As was expected, the farther the glider was pushed against the rubber band, the greater velocity it sustained when released down the track. We recorded the data and designed a graph with the Vernier app on our iPads. An "LOL" chart was also used to describe the Law of Conservation of Energy in this experiment.

                                                               
   
                            Ex: Rubber Band
     LIIx         O          LxII         
      Beginning            System                Energy
       Energy                                            After

                                                                     Reflection:

This experiment satisfies the question, "How are energy and velocity related?" The greater the energy, the faster the velocity is achieved. We also discovered, using the Law of Conservation of Energy, that energy was not gained but was merely transferred. The rubber band created potential energy that was transferred over to the glider as kinetic energy. Our graph shows the data points are slightly off the best- fit line, proving some human error still occurred.

                                                                                         


                                                                                                Real-World Connection:

                                                                                         A wrestler uses an attack move that applies a similar physics concept. They often lean against the ropes or boundaries of the arena in order to provide greater kinetic energy for their attack against an opponent.

Rubber Band Lab

                                                                     

                                                                Design:

In essence, the purpose of the "Rubber Band Lab" was to determine the relation between force and distance. Our group pulled a rubber band along a ruler-like apparatus (depicted above) at distances ranging between 0.01 meters and 0.05 meters. Using an electronic force probe, we measured the amount of Newtons required to pull the band back at a certain distance. We attempted two to three trials for each distance in order to minimize human error. A graph was made using Force (N) along the y-axis and amount of stretch (M) along the x-axis. The formula Fs=KX was used for the creation of this graph. Through our data we determined that K=130N/M. Another formula was used for elastic potential energy Us=1/2kx^2. The elastic constant of 130 equals k in the formula.

                              Reflection:

Human error was a major factor in this experiment. Slightly varying lengths and ways of pulling the rubber band, small technical issues, and etc. culminated into inaccuracies of the data. Using our data, we came up with K=130 N/M, which was much higher than the class average. (Many other groups in the class had completely different numbers). The obvious observation was that the farther the band is pulled, the greater amount of Newtons are required to pull it back, also increasing its potential energy.





                                   Real World Connection:

Slingshots apply a similar concept to this experiment. The farther the band is pulled back the greater amount of potential energy the object in the basket has. Greater distance pulled leads to the object being propelled farther and further.


                                                            Slingshot Video:

Pulley Lab

                                                               
                                                                   Design:

In this lab, we built a pulley system in order to lift brass objects. Without using the pulley we determined that it required 2 Newtons to lift a 0.2 kg brass mass 10 cm, using the formula 10N/kg. We used a LabQuest electronic probe to measure Newtons while the pulley was being used. It was calculated that only 1.2 Newtons were needed to carry the same object to the same height. The length of our string was measured as 28 centimeters. Two bar graphs (with pulley and without pulley) were drawn to record our data. The x-axis was labeled "distance" and the y-axis was labeled "force." The graph measured area of a force and distance, (A=DF) becoming energy. Other related formulas are Work=(Force)(Distance) and Joules=(N)(M).

                                                                                        Reflection:


Because of this lab, we discovered the length of the string and the size of the pulley relates to the amount of force required on an objects. The longer the string and the larger the pulley decreases the Newtons needed to carry the brass mass. The graph proves that increased distance, leads to decreased force and vice versa. It is known as a trade-off or an inverse in mathematical terms.

                   

                                                                       Real-World Connection:

The pulley is one of the many simple machines that makes our lives easier. Cranes are important tools found in construction sites that implement a pulley-like system to carry tremendous objects. The pulley in our experiment was like a crane but at a much smaller scale.
                                                           

Fun Facts:

• Hero of Alexandria, an ancient Greek engineer and mathematician, identified the pulley as one of the six simple machines used to lift weights.
• A pulley is also called a sheave or drum.
• The definition of a pulley is "a wheel on an axle that is designed to support movement of a cable or a belt along its circumference."

Here is a  a video on youtube that explains how pulley systems work. Runs for about 3 mins.

Mass vs. Force Lab

                                                               Design:

During the first week, we conducted the "Mass vs. Force" lab. For this lab, we used a manual probe and an electrical (LabQuest) device to measure the amount of newtons needed to lift up brass objects of varying masses (between 200g and 1000g). The grams were converted to kilograms and we recorded the different sets of data on our iPads. We then took this data and created a graph. 

                                                                   
                                                              






                                                               Reflection:

We discovered that ten times the number of kilograms was the amount of newtons required to lift the brass mass. For example, 2 Newtons was the minimum force needed to support 0.2 kilograms. We created a best fit line on a graph, using the equation y=mx=b. The newtons became 10x (y=10x) and there was no "b" because the line went through the origin. The equation for the gravitational constant of Earth is F=mg (10 kg/N becomes g). Also through our data collection and observations, our group determined that the electrical device was much more accurate and exact but that the manual force probe was more reliable. 
                                                                                                                                                                            

                            

            Real World Connection:

A typical space shuttle has a mass of 29,390 kg (4.5 million pounds) and needs to reach 17,500 mph in order to attain global altitude. Using the 

formula, I deduce that it requires 290,390 Newtons to 
adequately lift the shuttle from its earthly bonds.