Kinematics - Part 2

Here is the forty-fifth episode of Quantum Foam, Kinematics - Part 2. Let's get back to acceleration. It is a vector quantity that is defined as the rate at which an object changes its velocity. If an object is not changing its velocity, it is not accelerating. We can look at constant acceleration. You can show that a diagram's values are changing at 10 meters per second. The velocity is changing by a constant amount. As an object falls near the surface of the Earth, it accelerates downward. An object falls 5 meters in the first second, 15 meters in the second second, 25 meters per second in the third second, and 35 meters in the fourth second. It is going faster each consecutive second. The speedometer is an approximation. For objects with a constant acceleration, the distance of travel is directionally proportional to the square of the time of travel. Calculating average acceleration is also likely important. This is over an interval of time. It is final velocity minus initial velocity all over time. T is for the time taken for this change in velocity. 10 meters per second per second is the same thing as 10 meters per second squared. We are aiming towards beginning physics students here. Physics is quite a complicated subject. We all understand meters per second squared and miles per hour per second. There is a direction of the acceleration vector. We usually use a Cartesian graph to write an objecting going in the positive direction by going left to right down the x-axis. If an object is slowing down, the acceleration is negative. An object is accelerating if it is changing its velocity. When an object is speeding up, the velocity is in the same direction as the acceleration. The world that we study in physics is a physical world. We need to be able to set up situations as before, during, and after an event. We use words, graphics, numbers, equations, and diagrams. We focus on the use of diagrams to describe motion. There are vector diagrams. We have position time graphs. The line on a position time graph reveals useful information about the velocity. As the slope goes, so does the velocity. Curved lines have changing slope. The curved line of changing slope is a sign of accelerated motion and changing velocity. Negative slope means negative velocity. Rise over run is the slope of the various types of graphs. The principle of slope is incredibly useful for extracting relevant information about the motion of objects as described by their position verses time graphs. There is also velocity time graphs to consider. The area under the curve of a velocity time graph is the displacement distance traveled by an object. The lines on a velocity time graph reveal useful information about the acceleration of the object. If the acceleration is 0, then the slope is 0. If it is positive, there is an upward sloping line. If the acceleration is negative, then the slope is negative. There could be either a positive or negative velocity. These types of graphics are being taught at the eighth grade level. A free falling object is falling under the sole force of gravity. Ignore air resistance for these calculations. The force due to gravity is negative 9.8 meters per second squared. Acceleration happens even if it is negative. If we were to get further into this subject, we would begin using Kinematic Equations.