Unit 1 Summary

Reflection

In the first unit of Physics, we have covered five major concepts pertaining to Newton's First Law. With each concept building on the one before, it was crucial to completely understand an idea so that you could recognize it in later concepts.

The first idea that we tackled was Inertia, and we saw it firsthand when we rode the hovercraft. Inertia is measured by mass, and is the word that sums up the idea of things liking to stay where they are. Newton's First Law states that, "An object in motion/at rest will stay in motion/at rest unless acted on by an outside force." When we rode the hovercraft, it was already in motion, so it stayed that way until an outside force (a classmate) stopped me.
In this video, the toy car is pushed and is moving and remains in motion until it hits the phone (outside force).

The second concept that we discovered in Unit 1 was the relationship between Net Force and Equilibrium. Net Force is the total amount of force (measured in Newtons) put on an object. If unequal amounts of force are being put on an object from different sides, the difference between the two force values would equal the Net Force. If the Net Force = 0, then the object is at Equilibrium. One of the things that was interesting to me is that an object can be in Equilibrium while at rest, but also when it was moving at constant velocity.
This picture shows the two different force values yielding a net force of 20 N.



The third concept we discussed was Velocity and Acceleration. Velocity is the speed of an object going strictly in one direction. V is shown by using vectors (arrows) that show which way the force is going. The most common unit of measurement for V is meters per second which is written as m/s.
Building off of Velocity, the other way to show speed is Acceleration. Acceleration can be measured in varying directions and is measured in m/s^2. The formula to find A is the (change in velocity) divided by (time), and there are three ways to change the Acceleration: Change in direction, increase in speed, and decrease in speed.
Both of these forms of speed can be constant, where they have two formulas to show each the "how fast" and "how far" of an equation.

Constant V                      Constant A

How Far                                         d=vt                                 d=1/2at^2

How Fast                                        v=d/t                                v=at

Lastly, we worked on taking information from graphs and putting the information into one of the equations shown above. The y-axis value is seen as the (y) in the y=mx+b equation. The x-axis value represents the (x) in the equation, and the (b) is ignored for right now. Another helpful hint when transferring data is that m(slope)=1/2 acceleration. In most instances, the "How Far" equation was used, and all of the other variables were given except for the 1/2a, but it can be substituted by the slope.

Connections

When the unit first started, I anticipated that I would see physics in my everyday life to some extent, but I notice it much more than I thought I would. For example, I saw Net Force when I was watching the football game last week. David and Kokayi both went to tackle someone, and Kokayi had more force. He moved the three of them (Kokayi, opponent, David) in the direction he was going because he was already going in that direction and he had more force than David.

Podcast

Post Hovercraft Blog

Riding on the hovercraft felt like nothing I have been on before. Of all the rides at Disney World, this was exceptional. The only thing I can compare it to would be the magic carpet from Aladdin. You are physically sitting on a surface, however that surface is floating in the air. If I could tell someone what to expect, it would be that it was a really strange feeling. Not good or bad, but something I would want to do again to get a better understanding of how I felt about it.
I learned about the three phases of the activity: the push, the gliding, and the stop. I learned that the one push that I got at the beginning would be the same remnants of the force if I was half a mile away. During the middle stage where there are no forces acting on the hovercraft, there was no net force but I was still moving. This concept was hard to wrap my head around at first, but makes more sense now.
According to this lab, acceleration relies on an outside force. Not much is needed, but once the force has acted on the object, it could move in that direction forever unless disturbed by another force.
During the middle section of the hovercraft ride would be when I would expect to have constant velocity because that is when there are no outside forces acting on the hovercraft such as the push and the stop.
Some members were harder to control because they have more mass. The initial push made all the difference in where the hovercraft went, and reset when the other group members caught the person and turned him around to be sent back across the gym. The lighter group members were easier to push because they have a lesser ability to control where they go.

Newton's 1st Law Resource

This was the first video I found when looking for resources, and it summed up Newton's First Law extremely well. Although it was meant for kids, it stated the law which says, "Objects at rest or in motion will stay in the same state unless disturbed by an outside force." This video explains how your body reacts to inertia in the most common way that most people experience: modes of transportation.




In this photograph, the bus is coming to a sudden stop with a load full of people. The bus is in motion but with the force from the brakes, it is rapidly slowing down. As you can see, the people are leaning forward just as the bus is moving forward trying to stop. This object is in motion, and unless otherwise affected by an outside force, it will keep moving in the same direction according to Newton's First Law.




In this video the car is moving because of an outside force, and your body naturally wants to follow the direction of the car because it is contained inside the car. The force would be whatever hits the car from behind or whatever object your car hits head on. Your body will go the same direction as the momentum of the vehicle, but with the help of seat belts and head rests, the damage would be lesser. Newton's First Law states that, "An object at rest or in motion will stay at rest or in motion unless acted on by an outside force." This is a good example because both the car and the person are in motion, and they naturally want to go the same direction as the car, but the safety restraints help the person stay inside the car.