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