Key motion defs

Kinematics is the motion of something in a straight line.

1st boring but important definitions, they can test this stuff. Oh yes, they can.

d - is displacement. This is different than distance. Distance is the total number of meters you've gone while displacement is the difference in meters between where you start and end. For example, when you walk around the block you're distance might be 300 meters but you're displacement is zero because you ended where you started.

v - is velocity. The key with velocity is that its a combination of speed AND direction. They love to test this concept. So if you drive 30 mph thats your speed, but your velocity would be 30mph Northwest. You need to have both the speed and direction to have velocity. A big tested concepted is that you can change velocity by either changing speed OR direction. So if you now went 40mph you would have a new velocity or if you went Southeast you would also have a new velocity.

a - is acceleration. Acceleration is defined by its equation = (change in velocity)/(change in time). Any time you change your velocity (remember by either changing your speed or direction) you are accelerating. Think about in your car you step on the "accelerator" pedal or you turn the wheel and you are accelerating.


Equations are coming next. I love a good equation.