Describing and Determining Motion Describing Motion An object

Describing and Determining Motion

Describing Motion – 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

• Relative Motion – 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.

Calculating Speed – 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

• Average 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 – 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__

Different Slopes – Steeper the slope the __FASTER__ the movement • __HORIZONTAL__ line means no speed change