Post on 23-Feb-2016
description
MOTION
Motion
Speed describes Motion
Motion
Speed describes Motion Describes rate at which an
object moves
Motion
Speed describes Motion Describes rate at which an
object movesCalculated by distance/time
Motion
Speed describes Motion Describes rate at which an
object movesCalculated by distance/time
s=d/t
Motion
Speed describes Motion Describes rate at which an
object movesCalculated by distance/time
s=d/tSI unit of
measurement=meters/second
Motion
Rate of motion varies for different
moving objects~this variation requires appropriate units of
measurement to accurately describe an object’s speed
Motion
For example:m/s works well for describing
the speed of a rocket escaping Earth’s atmosphere
a rocket’s escape speed is measured in km/s
a rocket’s escape speed is measured in km/s
& is app. 34 xs faster than the speed of sound(Mach 34)
Geological plate movement is expressed in centimeters/year
It has taken app. 300 million years for plates to move to where they
are today
Consider a car traveling at highway speed…
miles/hour is the units of measurement given for a car’s
speed (in America)
most other places use the metric system when
expressing car speed
A car’s speedometer gives instantaneous speed which is
speed at a given point in time
Motion
Velocity also describes Motion
Motion
Velocity also describes Motion Describes speed with a directional
component
Motion
Velocity also describes Motion Describes speed with a directional
componentalso calculated by distance/time
Motion
Velocity also describes Motion Describes speed with a directional
componentalso calculated by distance/time
v=d/t
Motion
Velocity also describes Motion Describes speed with a directional
componentalso calculated by distance/time
v=d/tSI unit of
measurement=meters/second
Traveling 100 ml/hr southbound on I75 to Key West is an example of velocity.
Motion
Acceleration is another term used to describe motion
Describes the rate of change in velocity
Calculated by change in velocity/time interval
Δv/Δt or vf – vi/tf – tiSI unit of
measurement=meters/second/secondm/s2
Horses on a moving carousel is an example of motion with constant
speed but changing acceleration
Motion
Force affects Motionby altering speed and/or
direction
Motion
Friction is an example of a force that slows an object’s motion
MotionConsider applying the brakes
while driving…
Motion
~it is the combination of brakes slowing vehicle's acceleration & friction between the tire & the
road which slows/stops the vehicle’s motion
MotionConsider another force…
Gravitational force value=9.8m/s2
Motion
Throw a ball up & & the coming what happens back down?to the ball’s motion/speed going up
MotionWords, sketches, diagrams, data tables, graphs, & equations are
used to describe & analyze motion
MotionFor example:
Motion can be graphed on a position-time graph aka
distance-time graph
MotionFor example:
Motion can be graphed on a position-time graph aka
distance-time graphTime is plotted on the x axis
Position (distance) is plotted on the y axis
Motion
MotionPosition-time graphs can be
used to find the speed (velocity) & position of an object
MotionThe slope of a line of the
position-time graph is equal to the average speed (average
velocity) of the object’s motion.
MotionThe slope of a line of the
position-time graph is equal to the average speed (average
velocity) of the object’s motion.
MotionThe slope of the line can be
calculated byΔdistance/Δtime
df – di/tf - ti
Monday 8-27-12~QUIZ tomorrow~continue with your concept map creations~transfer post it note layout & content to paper~each student should have a written splay to study from~Ch2 Test Friday Sept. 7