>> Newtons First Law:
Newton's first law states that an object at rest (or motion) will stay in motion (or rest) unless acted upon by an outside force.
The picture above shows something that one could do to show inertia in action. When the person pulls the piece of paper, they are acting as an outside force. You may think that the coin will move with the paper, but silly you. Though there is a force on the paper, there is not a force acting on the coin. So,when the paper moves, the coin will not change positions, thus, falling down into the cup. We have tested and learned about many other examples like this one, like pulling a table cloth from under your dishes, or leaving a cup on your trunk. They all have a similar explanation to the example shown above.
>> Equilibrium and Net Force:
In this section, we learned what both net force and equilibrium are, as well as how to calculate the net force on an object.
In the image above, the little blue box has a net force of 0N. Force is measured in Newtons (N) which is equivalent to about 1/4 of a pound. We can figure this out by subtracting the force from one side by the force on the parallel side. To find net force you must add or subtract parallel forces, otherwise it is not a correct net force. When an objects net force equals zero, the object has achieved a state of equilibrium. An object has reached an equilibrium either when it is at rest or in constant motion. If the force on one side of an object is greater than the parallel force, the net force will not equal zero. Also, if you were to try to push a box that was 5kg and a box that was 50kg, you would have to use greater force on the 50kg box. This is not because it is heavier, but because it has a larger mass, which means there are more atoms to make move in one direction.
>>Speed and Velocity:
Speed is how far an object travels in a set amount of time. You may think that speed is the same thing as velocity. I did, but it isn't. The big difference is that velocity is direction specific, meaning that the velocity will change if the direction of the object changes. So, though you can drive at a constant speed, if you change direction, you will not be traveling at a constant velocity. Velocity changes also when an object accelerates, or accelerates in the opposite direction (slows down).
To find an objects velocity, you must know distance the object has traveled, and how long it has traveled. The equation to find velocity is
velocity=distance/time
You can also plug in the values and move around the equation to fit the specific problem.
>> Acceleration:
Acceleration is the rate at which an object's speed is increasing. Acceleration can be calculated by using the following equation
acceleration= change in velocity/time
The acceleration of an object can be increasing, decreasing, or constant.
In example A, the acceleration will be constant. In B, the acceleration is increasing and in the final example, C the acceleration is decreasing.
When writing acceleration as units, it must be written as m/s^2.
Another important formula to know that applies to acceleration is
distance=1/2(acceleration)time^2
This equation is used to calculate the distance that an object has traveled when the given acceleration is constant.
>>Graphing:
We are able to use the acceleration data we collect as points on a graph by using time as our X coordinates and velocity as our Y coordinates. You can put these points into Excel, and go through the steps to calculate a line of best fit. The equation of a line is actually very similar to one of the equations that we use.
Equation of a line: y=mx+b
Formula for distance with constant acceleration:d=1/2at^2
In this class, the b value is so close to zero that we do not use it. In the equations, m(slope) is 1/2a and x is interchangeable with t^2. By using the equation of the line, we are able to calculate the acceleration of an object.
For a further explanation of what you need to know about graphing, here is a video that my group and I made:
YAY PHYSICS!!!
Wow, my first comment is that this is amazing. You went over the top with diagrams, equations, and even explanations. The visual aid was extremely relevant and helpful in describing each concept carefully. Also, the idea of putting main key facts in bold and bigger font was, again, really helpful. I have no real criticism other than it was a little difficult to read the font you used, you might just want try to make it a little bigger. All in all, it was an honor to read your blog. Actually.
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