displacement, - glenbard west high school 1 motion szarzak/unit 1... · · 2017-12-04distance vs....

Distance vs. Displacement,

Speed vs Velocity, and

Velocity vs Acceleration

Distance vs. Displacement,

Speed vs Velocity, and

Velocity vs Acceleration

MotionMotionMotion

Megan is in MotionDavid is in

Motion

• Everything in the universe is in motion.How do we know?


MotionMotionMotion• Everything in the universe is in motion.How do we know?

• World is rotating


• World is rotating


• World is rotating• World is revolving


• World is rotating• World is revolving


• World is rotating• World is revolving• The Solar System is

revolving around a galactic center







• The Universe is expanding









• Motion is Relative

Hi Dad! Hi Mom!

REFERENCEMotionMotionMotion• Everything in the

universe is in motion.How do we know?




• Motion is Relative• Everything has its own

reference frame ﴾Shout out to Einstein﴿

NOTES...LIVE AND IN COLOR!!!

Motion: Speed:• Measure of how fast something is moving • Speed =

• Speed is a rate: “something divided by time”

• SI units for Speed: (m/s)

DistanceTime

Velocity is a vector (magnitude and direction)

Instantaneous Speed – speed at any given moment of time

Average Speed – total distance covered over a time interval

Speed is scalar (magnitude but no direction)

Instantaneous Speed vs Average Speed

1﴿ Scalar Magnitude only

2﴿ Savg =

Savg = average speed

t = time

d = distance

d t

1﴿ Vector Magnitude & Direction

2﴿ vavg =

vavg = average velocity

t = time

d = DISPLACEMENT

d t

Speed: Velocity:

Motion:Distance:How far you travel.

Displacement:How far you are from where you began (your POSITION).

Units:

s2

m Ways to Accelerate:Speed upSlow downChange direction

Acceleration:

Change in velocityChange in time

a = ΔvΔt

Gravity is an accelerationGravity = 9.8 m/s2

SPEED Example:

ACCELERATION Example:

I would suggest you take notes like this:

Savg = dt x t t x

St = d

d = Std = (12 m/s)(10. s) = 120 m

Given: S = 12 m/s t = 10. sFind: d = ???

a = 2.5 m/s2==m/s s

mxx s

1== s2

ms

m/s

2.5 =30 m/s 25 m/s 2.0 s 0.0 s

=v2 v1 t2 t1

ΔvΔt

a = = s

If my car accelerates from 25 m/s to 30 m/s in 2.0 seconds, what isits acceleration?

UNITS:UNITS:

• Measure of how fast something is moving• Measure of how fast something is moving• Measure of how fast something is moving

• Measure of how fast something is moving

• Speed =


• Speed =


• Speed = DistanceTimeDistanceTime

DistanceTime


• Speed =



• Speed =



• Speed =


DistanceTime

DistanceTime

DistanceTime


• Speed =




• Speed =




• Speed =



DistanceTime

DistanceTime

DistanceTime

Velocity is a vector (magnitude and direction)




1m/s 1m/sOR

Who says direction doesn't matter?

Who says direction doesn't matter?

Speed: Velocity:1) Scalar Magnitude

only

2) Savg =

Savg =

t = time

d = distance

d t

1﴿ Vector Magnitude & Direction

2﴿ vavg =

vavg =

t = time

d = DISPLACEMENT

d taverage velocityaverage speed

Distance:How far you travel.

Displacement:How far you are from where you

began ﴾your POSITION﴿.

What's the Difference???

What distance did I travel?

Distance or Displacement

?

SPEED

Title Page

SPEED

1) If Usain Bolt can maintain a constant speed of 12 m/s, he will cover 12 meters every second. At this rate, how far will he travel in 10. seconds?

Need for Speed:

1.

1

1) If Usain Bolt can maintain a constant speed of 12 m/s, he will cover 12 meters every second. At this rate, how far will he travel in 10. seconds?

1.

Need for Speed:

Savg = dt x t t x

St = d

d = St

d = (12 m/s)(10. s) = 120 m

2) If Usain Bolt can maintain a constant speed of 12 m/s, he will cover 12 meters every second. At this rate, how far will he travel in 1 minute?

Need for Speed:

2.

2

2) If Usain Bolt can maintain a constant speed of 12 m/s, he will cover 12 meters every second. At this rate, how far will he travel in 1 minute?

Need for Speed:

2.

1 min x 60 s1 min = 60 s

d = St

d = (12 m/s)(60 s) = 720 m

( )

Title Page

a = ∆v / ∆t a = ∆v / ∆t



Ways to Accelerate:Ways to

Accelerate:

a = ∆v / ∆t a = ∆v / ∆t



Ways to Accelerate:Speed up

Ways to Accelerate:Speed up

a = ∆v / ∆t a = ∆v / ∆t



Ways to Accelerate:Speed upSlow down

Ways to Accelerate:Speed upSlow down

a = ∆v / ∆t a = ∆v / ∆t



Ways to Accelerate:Speed upSlow downChange direction


a = ∆v / ∆t a = ∆v / ∆t



Units:Units:



a = ∆v / ∆t a = ∆v / ∆t



Units:

s2 m Units:

s2 m



a = ∆v / ∆t a = ∆v / ∆t



Use 2 SIGFIGS!!!Use 2 SIGFIGS!!!

If my car accelerates from 25 m/s to 30 m/s in 2.0 seconds, what is its acceleration?

1

ΔvΔtΔvΔta = a =


v2 v1t2 t1v2 v1t2 t1

ΔvΔtΔvΔta = a = ==


30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

= 2.5 2.5 =30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

= 2.5 2.5 =30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

UNITS:UNITS:

==

m/s ssm/s

= 2.5 2.5 =30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

mssm xx 1

ss1UNITS:UNITS:

==

m/s ssm/s

= 2.5 2.5 =30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

mssm xx 1

ss1 == m

s2 s2

mUNITS:UNITS:

a = 2.5 m/s2a = 2.5 m/s2

==

m/s ssm/s

= 2.5 2.5 =30 m/s 25 m/s 30 m/s 25 m/s 2.0 s 0.0 s2.0 s 0.0 s==v2 v1

t2 t1v2 v1t2 t1



m/s ssm/s

mssm xx 1

ss1 == m

s2 s2

mUNITS:UNITS:

a = ΔvΔta = ΔvΔt

Gravity = 9.8 m/s2Gravity = 9.8 m/s2

Gravity is an:Gravity is an:

Gravity is constant on Earth. It causes the same rate of acceleration for ALL falling objects.

Gravity is constant on Earth. It causes the same rate of acceleration for ALL falling objects.

DEMO TIME:If I drop these at the same time, the constant acceleration of gravity implies they should hit the ground at the same time. Will they???

DEMO TIME:HOW ABOUT

NOW???

displacement, - glenbard west high school 1 motion szarzak/unit 1... · · 2017-12-04distance vs....

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