Download Describing and measuring MOTION

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