Motion

Describing & Measuring Motion

Chapter 1

Section 1

Motion

• When an object’s distance from another object is changing– Its all Relative!!!

• Earth moves at ~100,000 km/hr around the sun

Reference Point

• A place or object used to determine if something else is in motion

International System of Units

• SI Units– Based on the number 10

• 1 meter = 10 decimeters• 1 meter = 100 centimeters• 1 meter = 1,000 millimeters• 1 kilometer = 1,000 meters

Describing Distance

• SI unit for length is…– Meters

• Kilo-– 1000x

• Centi-– 1/100th

• Milli-– 1/1000th

Calculating Speed

• The distance an object travels, divided by the time it took– V=d/t

• U.S.– Miles Per Hour

• Mph

• Rest of the world– m/s– Km/hr

Constant vs. Average Speed

• Constant Speed– Never changes

• Cruise control

• Average Speed– The total distance

divided by total time

Describing Velocity

• The object’s…– Speed– Direction

• Tornado’s speed– 30 km/hr

• Tornado’s velocity– 30 km/hr NE

Graphing Motion

• Constant Motion• Acceleration• Deceleration• Stopped• Moving Forward• Moving Backward