1D+Kinematics

= 1 Dimensional Kinematics =

Kinematics involves the concepts of Vecotors/Scalers, Distance, Displacement, Velocity, and Acceleration.

** Vectors/ Scalars **
When measuring a certain quantity you have to make sure your answer is correctly written and defined. A scaler is a measurement that only has one value like speed. Speed is merely a value that defines how fast something is moving. Whereas Velocity is a vector quantity that states how fast something changes position which is why it is measured in two different quantities such as meters per second or Miles per hour. The entire basis of physics relies of Scalers and Vectors. The actual definition of a vector is a value that has a magnitude (size) and a direction, whereas a scaler has only a magnitude.

Distance/ Displacement
Distance and Displacement are two very different things. If a person travels 500 feet west and 200 feet east right afterwards the total distance traveled is 700 feet, but the displacement is only 300 feet, why? Well lets go over that. Distance is the measure of how far something has traveled total so 500 feet west + 200 feet east = 700 feet total, and if someone has traveled 700 feet west, 1200 feet north, and 1300 feet east they've traveled 3200 feet. Now displacement is another concept. Displacement is the total distance from the starting point in a straight line. This can be confusing so lets draw a picture... Now, obviously the distance traveled and the displacement are much different. As you can see the Displacement is much shorter than the distance traveled. If a person goes 400 feet west, then 200 feet west what is their displacement? If you guessed 200 feet you're correct. Knowing the difference between Vectors and scalers is very key to understanding physics notation. Distance and Displacement rear their ugly heads again in 2D Kinematics. **Velocity** Velocity is the change in position over the change in time, or in equation form (Delta)X/(Delta)T = V Don't confuse this with speed, these are two different quantities that are __not__ interchangeable. Lets say someone travels 300 feet in 1 minute. then in simplest terms, their velocity is 300 feet per minute!! Now this is average velocity. This is the velocity that is averaged out over time not the "Instantaneous Velocity." Instantaneous velocity is calculated to a certain degree. Because it is based on a very specific range it can only be calculated physically to a certain degree. Velocity is one of the most important building blocks in physics which goes all the way through the semester.

**Acceleration** Acceleration is the Change in Velocity over the change in Time or in equation form (Delta)V/(Delta)T = A. When things change velocity be it an increase in speed or a decrease in speed it is always called acceleration. Deceleration should not be used to talk about a negative acceleration. Now the fun part. Throw anything into the air and see what happens. It falls. that's obviously due to gravity. Everything falls at a uniform rate at 9.8 m/s/s. that means that your acceleration downward is -9.8 meters per second per second. If you want to find somethings velocity after falling for 5 seconds you multiply 9.8 by 5 and that tells you that after 5 seconds of falling any particular object will always be at 49 meters per second at 5 seconds!! pretty easy right?? [|Here is a great demonstration.]