UNIT 1: KINEMATICS
Brief Overview
When we think about Physics the first thing that comes to mind might be the motion or trajectory of a ball in the air. This is kinematics, one of the most fundamental topics in physics. In this unit, we explored the position, velocity, acceleration, displacement, and time of objects in motion.
TERMINOLOGY
POSITION
The position is the place where a person is. in respect to the origin or initial position. For example, if someone's position was 2 miles they would be 2 miles away from the origin.
DISPLACEMENT
Displacement is the measurement of where someone has moved to in respect to their initial position. Someone may have walked ten meters but if that was 5 meters forward and 5 meters back, their displacement would be zero.
DISTANCE
Distance is the actual amount the object has traveled. So if a cyclist biked 10 miles, even if it was a roundtrip, his distance would be 10 miles.
INTERPRETING GRAPHS
Position- time graphs
A position time graph supplies us with a variety of information. Not only are we given the position of the object at any given time using the (x,y) coordinates, but we can also determine the velocity of the object at any given time using this graph. To determine the average velocity from one time to another time you divide the difference in position by the difference in time. If the number is positive then the velocity is in the positive direction, and if it is negative the object is moving in the negative direction.
MY SKILLSET
ACCELERATION
In order to find acceleration from a position-time graph, you must find the tangent lines at the two points in between which you want to find the acceleration. To find the acceleration divide the difference in velocities by the time elapsed.
STARTING VELOCITY
In order to find the starting velocity from a position-time graph use the formula d = Vi*t + 1/2at^2.
INTERPRETING VELOCITY-TIME GRAPHS
POSITION
Given the initial position, you can find the position at a time by multiplying average velocity by time and adding this to the initial position.
DISTANCE
To find the distance travelled by an object using a velocity-time graph, you simply multiply the difference in velocity by the time elapsed.
DISPLACEMENT
Given a velocity-time graph, to find the displacement calculate the area under the curve to find displacement.
INTERPRETING
CONNECTING REPRESENTATIONS OF MODELS
The velocity-time graph is the derivative of the position-time graph and the acceleration-time graph is the derivative of the velocity-time graph.
SOLVING PROBLEMS USING CONSTANT VELOCITY AND UNIFORM ACCELERATION MODELS
Using the variables discussed earlier in this page you can solve any problem.
PROJECTILE MOTION
A projectile is an object that travels through the air without "touching" the air. Meaning that it doesn't change the air around it.
