HW Due today

Read and Study 2.4 (p.15-16) Do RQ #9-14 (p. 26, concepts, no math)Need a refresher? Read 2.3, and redo RQ #7-8

HW assigned today

Sell a Car project is due Oct. 28.

TONIGHT’S HW : Read and STUDY 2.0 – 2.4.Finish up to #19 in the POGIL(you will get done most of this in class today)

Do Now Is ACCELERATION a scalar or vector quantity? Add it to your T chart from last class Then, turn to page 2 of your Concept Attainment/ POGIL from last class. You have 3 minutes to rearrange the acceleration formula:

HW Due today

Read and Study 2.4 (p.15-16) Do RQ #9-14 (p. 26, concepts, no math)Need a refresher? Read 2.3, and redo RQ #7-8

HW assigned today

Sell a Car project is due Oct. 28.

TONIGHT’S HW : Read and STUDY 2.0 – 2.4. Finish up to #19 in the POGIL(you will get done most of this in class today)

Do Now Is ACCELERATION a scalar or vector quantity? Add it to your T chart from last class.Then, HYPOTHESIZE the BIG IDEA on page 1 of your

POGIL from last class. Use the YES?NO boxes to complete the Concept Attainment

YES (correctly shows today’s new concept) NO (does NOT show today’s new concept)

Increasing your velocity from 50 km/h 60 km/h (in the north direction)

Decreasing your velocity from 60 km/h 50 km/h (in the south direction)

Driving north at a constant 50 km/h and then making a sharp turn east at 60 km/h

Driving north up to a four way intersection, stopping, and making a left turn west

Driving at a constant 50 km/h NORTH Driving at a constant 60 km/h SOUTH Driving in a straight line at 50 km/h Driving up to a four way intersection,

ignoring stop sign, and keep going straight at the same speed you were going before (**don’t ever do this!)

Compare/contrast YES/NO boxes. List your hypothesis here…then check in!

List the BIG IDEA here when checking in with teacher….

PART 2: Concept Attainment:

YES (correctly shows today’s new concept) NO (does NOT show today’s new concept)

Increasing your velocity from 50 km/h 60 km/h (in the north direction)

Decreasing your velocity from 60 km/h 50 km/h (in the south direction)

Driving north at a constant 50 km/h and then making a sharp turn east at 60 km/h

Driving north up to a four way intersection, stopping, and making a left turn west

Driving at a constant 50 km/h NORTH Driving at a constant 60 km/h SOUTH Driving in a straight line at 50 km/h Driving up to a four way intersection,

ignoring stop sign, and keep going straight at the same speed you were going before (**don’t ever do this!)

Compare/contrast YES/NO boxes. List your hypothesis here…then check in!

List the BIG IDEA here when checking in with teacher….

PART 2: Concept Attainment:

IF velocity changes…THEN there is an acceleration

CONSTANT Velocity CHANGING

Velocity

a = Δv OR v2 – v1

Δt Δt

Δv = a Δt or v2 – v1 = a Δt

Δt = Δv or Δt = v2 – v1 a a

Magic Triangle!

OR…

So…just what exactly IS acceleration?

Let’s say a car has an acceleration of 2 miles per hour per second; in other words: 2 mi

h . sWHAT DOES THAT MEAN? Brainstorm with the people around you… Every 1 SECOND, the car’s velocity is

INCREASING by 2 miles per hour.

Time (s)

•0

Velocity (mph)

•0

A car has an acceleration of 2 miles per hour per second; in other words: 2 mi

h . s

Time (s)

•0•1

Velocity (mph)

•0•2

A car has an acceleration of 2 miles per hour per second; in other words: 2 mi

h . s

Time (s)•0•1•2

Velocity (mph)

•0•2•4

A car has an acceleration of 2 miles per hour per second; in other words: 2 mi

h . s

Predict the car’s velocity for the next 5 seconds

Time (s)•0 •1•2•3

Velocity (mph)

•0•2•4•6

Time (s)•0 •1•2•3•4

Velocity (mph)

•0•2•4•6•8

Time (s)•0 •1•2•3•4•5

Velocity (mph)•0•2•4•6•8•10

Time (s)•0 •1•2•3•4•5•6

Velocity (mph)•0•2•4•6•8•10•12

Time (s)•0 •1•2•3•4•5•6•7

Velocity (mph)•0•2•4•6•8•10•12•14

This chart shows data

for a CONSTANT, POSITIVE

acceleration

Clicker Concept Review

• Now that you have the FORMULA for acceleration, let’s see how well you can CONCEPTUALLY understand it.

• These questions are NOT in your POGIL• However, this PowerPoint is on my website;

feel free to print out the slides at home. Or, you can write your work on loose leaf now.

Two people are driving down the street; 1 in an old VW Beetle and 1 in a new Maserati. The person driving the Beetle goes from 25 to 30 mph in 5 seconds. The person in the Maserati takes his/her time, and goes from 25 to 30 mph in 30 seconds. WHICH CAR HAS THE LARGER ACCELERATION?

Two people are driving down the street; 1 in an old VW Beetle and 1 in a new Maserati. The person driving the Beetle goes from 25 to 30 mph in 5 seconds. The person in the Maserati takes his/her time, and goes from 25 to 30 mph in 30 seconds. WHICH CAR HAS THE LARGER ACCELERATION?

1 2 3 4 5

0% 0% 0%0%0%

1. The Beetle2. The Maserati3. Same acceleration4. Not enough info to say5. Not sure

Two people are driving down the street; 1 in an old VW Beetle and 1 in a new Maserati. The person driving the Beetle goes from 25 to 30 mph in 5 seconds. The person in the Maserati takes his/her time, and goes from 105 to 110 mph in 30 seconds. WHICH CAR HAS THE LARGER ACCELERATION?

1 2 3 4 5

0% 0% 0%0%0%

1. The Beetle2. The Maserati3. Same acceleration4. Not enough info to say5. Not sure

Think CONCEPTUALLY using EXAGGERATED EQUATIONS

Beetle Maserati

Same change in vDifferent times

Different accelerations

Remember…

• Directly proportional vs. Inversely Proportional

So, are ACCELERATION and TIME directly or inversely proportional?

1 2 3

0% 0%0%

1. Directly2. Inversely3. Not sure

Now, the person driving the Beetle goes from 25 to 45 mph in 20 seconds. The person in the Maserati goes from 25 to 125 mph in 20 seconds. WHICH CAR HAS THE LARGER ACCELERATION?

Now, the person driving the Beetle goes from 25 to 45 mph in 20 seconds. The person in the Maserati goes from 25 to 125 mph in 20 seconds. WHICH CAR HAS THE LARGER ACCELERATION?

1 2 3 4 5

0% 0% 0%0%0%

1. The Beetle2. The Maserati3. Same acceleration4. Not enough info to say5. Not sure

Think CONCEPTUALLY using EXAGGERATED EQUATIONS

Beetle Maserati

Different change in vSame times

Different accelerations

So, are ACCELERATION and CHANGE IN VELOCITY directly or inversely proportional?

1 2 3

0% 0%0%

1. Directly2. Inversely3. Not sure

Speed changes by…

Speeding Up

Slowing Down& / or

& / or& / or

If an object is CHANGING VELOCITY BY……

Speeding UpThen it is Positively

Accelerating

Slowing DownThen it is Negatively

Accelerating

Changing direction Then it is ACCELERATING (Centripetal acceleration… we will learn about

this in Ch. 9)

POGIL

• Aim to FINISH the POGIL…some may. Some may not.

• Remember to check in at STOP SIGNS• We ARE NOT reviewing as a class.• We are stopping with 5 minutes left in

class.

• Up to #19 is HW

20. True or False: Acceleration ONLY occurs if the speed INCREASES

1 2 3 4

0% 0%0%0%

1. True2. False3. Not enough info

to say4. Not sure

21. If velocity in a vehicle is CONSTANT, is the vehicle accelerating?

1 2 3 4

0% 0%0%0%

1. Yes2. No 3. Not enough info

to say4. Not sure

22. Suppose you are driving a car at a constant velocity of 50 mi/h. What is your acceleration?

1 2 3 4 5

0% 0% 0%0%0%

1. 02. Less than 50, but not 03. More than 504. Not enough info to say5. Not sure

23. Suppose a car moving in a straight line steadily increases its speed each second, first from 35 to 40 km/h, then from 40 to 45 km/h, then from 45 to 50 km/h, What is its acceleration?

1 2 3 4 5

0% 0% 0%0%0%

1. 02. 5 km/h s3. Less than 5 km/h s4. More than5 km/h s5. Not sure

24. In 5 seconds a car moving in a straight line increases its speed from 50 km/h to 65 km/h. During those same 5 seconds, a truck goes from rest to 15 km/h. Which has the larger acceleration?

1 2 3 4

0% 0%0%0%

1. Car2. Truck3. Same 4. Not sure

25. Is it possible to be moving but not accelerating?

1 2 3 4

0% 0%0%0%

1. Yes2. No 3. Not enough info

to say4. Not sure

26. Why is it that an object can accelerate while traveling at constant speed, but not at constant velocity?

27. Light travels in a straight line at a constant speed of 300,000 km/s. What is the light´s acceleration?

1 2 3 4 5

0% 0% 0%0%0%

1. 02. Less than 300,000 but

not 03. More than 300,0004. Not enough info to say5. Not sure

28. Which has more acceleration when moving in a straight line- a car increasing its speed from 50 to 60 km/hr, or a bicycle that goes from zero to 10 km/hr in the same time?

1 2 3 4 5

0% 0% 0%0%0%

1. Car 2. Bike3. Same 4. Not enough info to say5. Not sure