Motion Along a Straight Line Motion is defined in two areas:  Dynamics ­ Why the object is moving  Kinematics ­ Movement of an object  Where there is motion there is velocity (rapidity of motion or operation; swiftness or speed) Velocity:  Motion in terms of stopping, speeding up, slowing down, etc.  With velocity focus on time (any unit of time) and displacement (distance from “here” to “there”; the object’s change of position)  Time: t= t 2 t 1  Velocity: x / t (with x being displacement) ­ The SI units for velocity is meters per second (m/s) Example: Driving from “here” to “there” It takes 1hr to get from “here” to “there”; find the velocity. Displacement: X 2– X 1= 35km – 0km = 35km * 1000m / 1km = 35000m Note: Velocity is in units’ m/s so km needs to be changed to m (there are 1000m in 1km) Time: 1hr * 3600secs / 1hr = 3600secs Note: Velocity is in units’ m/s so mins need to be changed to secs (there are 3600secs in 1hr) Velocity: 35000m / 3600secs = 9.72m/sec Acceleration  The change of velocity of an object with respect to time  The SI units for acceleration is meters per second squarded ­ m/s 2 Note: Acceleration when gravity is the only force will be constant at ­9.8m/s 2 Example: Finding acceleration it takes 2secs to get from “here” to “there” (Vx = Vox + ax*t)(Vox being initial velocity; Vx being final velocity; ax being acceleration; t being time) Acceleration (just plug in #s) Vx