Describing and Determining Motion

Describing Motion Reference Points An object is in __MOTION__ if its distance from another object is changing. Reference Points A __REFERENCE POINT__ is a place or object used for comparison to determine if something is in motion. __STATIONARY__ objects make good reference points http://www.wimp.com/kittensfly/ (0:58) - How do you know these kittens are flying or in motion?

Relative Motion Measuring Distance The Earth moves at the speed of __30 KM__ every second. Measuring Distance __INTERNATIONAL SYSTEM OF UNITS__ system used to for a universal measurements. The SI unit of length is the __METER__. Centi- means _ONE HUNDREDTH_. There are 100 __CENTIMENTERS__ in a meter. Milli- means __ONE THOUSANDTH__. There are 1000 __MILLIMETERS__ in a meter. Kilo- means __ONE THOUSAND__. There are 1000 __METERS__ in a kilometer. BrainPop – Metric Unit (3:23) BP – Metric vs Customary (2:46)

Calculating Speed The Speed Equation If you know the __DISTANCE__ an object travels in a certain amount of __TIME__, you can find its speed. __SPEED__ of an object is the distance the object travels per unit of time. The Speed Equation Speed = __DISTANCE__ / __TIME__ 25 Mi/h is 25 __MILES__ in 1 __HOUR BrainPop – Distance, Rate (Speed) & Time – 3:36

Average Speed Instantaneous Speed __TOTAL DISTANCE__ / __TOTAL TIME__ = Average Speed 5 miles in 2 hour, 15 miles in 3 hour what is it’s average speed? __ 5 + 15 = 20 miles, 2 +3 = 5 hours So, 20 miles/5 hours= 4 miles / hour___. Instantaneous Speed __INSTANTANEOUS SPEED__ is the rate at which an object is moving at a given instant in time.

Describing Velocity When you know both the __SPEED__ and __DIRECTION__ of an object’s motion, you know the __VELOCITY__ of the object. Speed in a given direction is __VELOCITY__.

Graphing Motion Calculating Slope The steepness of a line on a graph is called __SLOPE__ Calculating Slope Slope = __RISE__ / __RUN__ The __RISE__ is the vertical difference or the __UP__ and __DOWN__ The __RUN__ is the horizontal difference or the __LEFT__ and __RIGHT__ Videos BrainPop- Slope and Intercept – 3:53

Different Slopes __HORIZONTAL__ line means no speed change Steeper the slope the __FASTER__ the movement __HORIZONTAL__ line means no speed change Gradual Decrease in speed Constant increase in speed Decrease, constant (no change), increase No change in speed