Unit+2+-+Acceleration

Acceleration Tutorials and Videos: [|Acceleration Info]

= = =Acceleration:= 1. Increase in the rate or speed of something. 2. The rate of change of velocity per unit of time. media type="custom" key="21246686"

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Acceleration is the **rate at which velocity changes**. It refers to **increasing but also decreasing speed or a change in direction**. Increasing speed is acceleration. An example of acceleration is when a car speeds up and passes another car.
 * What is Acceleration? **

The decreasing of speed is called **negative acceleration** or **deceleration**. Deceleration can be when you are running really fast in a race and when you reach the finish line you slow down and stop. A change in direction can also be acceleration. When a ball is hit it is accelerating because it changes its direction as it is hit. 

Calculating Acceleration To determine the acceleration of an object moving in a straight line, you have to calculate the change in speed per unit of time. Acceleration= Final Speed-Initial Speed/Time. The SI unit for acceleration is meters per second. Example: an airplane starts on the runway at 0m/s. Its final speed is 40m/s in a time of 5s. So the acceleration is 8m/s^2…. A=40m/s-0m/s/5s= 8m/s^2.



Graphing Acceleration You can use a speed versus time graph or a distance versus time graph to analyze the motion of an accelerating object. A slanted, straight line on a speed versus time graph means that the object is accelerating at a constant rate.

=Terminal Velocity:= When an object falls it accelerates due to its weight (the downward force of gravity acting on the objects mass). As it accelerates its velocity increases. The increase in velocity is accompanied by an increase in air resistance (drag). Eventually the air resistance acting upwards on the objects equals the weight acting downwards. The overall force on the object is balance or zero; it therefore cannot accelerate and continues to fall at constant velocity. This is referred to as the terminal velocity. The animation below shows the terminal velocity of a skydiver:  [|Click Here to View Animation] =Tutorials:=

When an object is slowing down, the direction of the acceleration is in the opposite direction of the object's motion.

Example Acceleration Problem:
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=Games and Practice:= [|Acceleration Battleship] [|Rags to Riches - Speed, Velocity and Acceleration] [|Who Wants to Be a Millionaire] [|Understanding Acceleration] [|Speed vs. Time Graphs Practice] [|Calculating Acceleration Practice]