Describing and measuring MOTION Section 1.1 Notes

Key Concepts When is an object in motion? How do you know an object’s speed and velocity? How can you graph motion?

Describing Motion You are in MOTION if your distance from another object is changing Depends on a REFERENCE POINT Place or object used for comparison

Describing Motion Are you moving? Reference point = SMARTboard Ref. pt. = Sun To determine motion, you must know your reference point!! Car vs. big truck or busses

Relative Motion Boat example: people in boat compared to shore – why? people in boat compared to boat – why?

Measuring Distance You use units of measurement to describe motion SI System Meter - basic

Review: How many cm in a m? How many mm in a m? How many m in a km?

Converting Units Practice Problem - Describing and Measuring Motion Converting Units Practice Problem How many centimeters are in 22.5 meters? 22.5 m = 2,250 cm

SPEED The distance an object moves in a certain amount of time Speed = distance / time Units depend on measures of distance and time m/s km/h m/h

Average Speed Overall speed of an object Calculate by dividing total distance by total time

Instantaneous Speed Rate at which an object is moving at a given instant in time. Why is the instantaneous speed different from the average speed?

Would a radar gun (used by police officers) measure average speed or instantaneous speed? WHY?

VELOCITY Speed in a given direction. You need to know the direction to know velocity Important to: pilots, weather forecasters, air traffic controllers

Graphing motion!! Motion graphs plot distance versus time Slope = rise/run Slope = distance/time Slope = speed of that segment

Graphing Motion

Graphing Motion Activity - Describing and Measuring Motion Graphing Motion Activity Cgp - 3011

Slow motion on planet earth 1.2 Notes

Key Concepts How does the theory of plate tectonics explain the movement of Earth’s landmasses? How fast do Earth’s plates move

Earth’s Plates Earth’s outer layer composed of plates Like pieces of a puzzle

Theory of Plate Tectonics Earth’s landmasses have changed position over time because they are part of plates that are slowly moving. Why do they move?

Convection Currents Hot matter rises, then cools and sinks Heat from the core causes convection currents in the mantle. Hot matter rises, then cools and sinks Earth’s plates move on top

Plate Movement Some plates move at a rate of several centimeters each year. Others - only a few mm per year.

Plate Movement Why don’t we feel the plates moving? SO slow Scientists use average speed of plates to predict future changes.

Continental Drift Activity - Slow Motion on Planet Earth Continental Drift Activity Cfp-1015