Warm Up (Page 21) 1. If Olivia drives at 68 mph for 5 hours,

how far did travel?

1. Mrs. Ward is taking a trip to Washington state over the summer break. If she travels at 70 mph for 24 hours, would she make it to WA? Why or why not? (p.s. How far do you think Washington is? Think critically!!!)

Announcements/Agenda

We need to review and complete our stations from yesterday.

Velocity and Acceleration Notes and Practice today

Speed it up!

Velocity: What is it?Velocity is a speed in a specific

direction.

Formula: v= d/t + direction

Examples of velocities:30 m/s to the left45 mi/hr west18 km/s up

Velocity Example ProblemsMejde was taking a rocket ship to his home in

outerspace. If the rocket travels 900 km in 2 minutes towards the sun, what is his velocity?

Ms. Britain is driving North to her parents’ home in New Hampshire. If she drives 720 miles for 12 hours, what is her velocity?

REMEMBER!!!!!!!Solve Velocity problems JUST LIKE SPEED problems. Just add in a DIRECTION.

Speed and Velocity….http://

www.youtube.com/watch?v=DRb5PSxJerM

AccelerationAcceleration is a change in velocity over time

What two components make

up velocity?

Velocity

Speed Direction

AccelerationDef.: Change in _________ over ___________Can be change in speed or direction (speed up, slow down, or change direction)

AccelerationDef.: Change in _velocity_ over __time____Can be change in speed or direction (speed up, slow down, or change direction)

Is this ball accelerating

?Yes! Because the direction is changing.

Cars B and C!

ABC

Acceleration is not just a change in velocity, it’s how fast that

change happens.

Car C!

ABC

Discovery Education Videohttp://player.discoveryeducation.com/index.cf

m?guidAssetId=A04DA40D-810B-4057-B333-7752AF27FAA2&blnFromSearch=1&productcode=US

To measure it, you must know the initial velocity, the final velocity,

and the time it takes to make the change.

AccelerationDef.: Change in velocity

Can be change in speed or direction

(speed up, slow down, or change direction)

Acceleration = ∆v/ t

Acceleration•Initial Velocity –Object’s velocity when you start measuring acceleration.

•Final Velocity –Object’s velocity when you finish measuring acceleration.

- Greek letter delta – “change”

Acceleration = change in velocity

time

a= vt

The unit for acceleration is m/s2.

v is the difference between the final velocity (vf) and the

initial velocity (vi).

v = vf - vi

AccelerationDef.: Change in velocity

Can be change in speed or direction

(speed up, slow down, or change direction)

Acceleration = ∆v/ t∆v = vf – vi

Example 1A roller coaster’s

velocity at the top of a hill is 10m/s. Two seconds later it reaches the bottom of the hill with a velocity of 26m/s. What is the acceleration of the roller coaster?

Answervf = 26 m/svi = 10 m/s t = 2 s

Acceleration = ∆v/ ta = 26m/s – 10m/s

2 sa = 16m/s

2sa = 8m/s/s or 8m/s2

Examples 2-4 – Try them!2. A car travels at 60 miles per hour

around a curve. Is the car accelerating?

3. A car travels in a straight line at 60 mi/hr. Is the car accelerating?

4. A car goes from 0 mph to 60 mph in 6 seconds. What’s the car’s acceleration?

Answers:1. Yes! Because it’s changing direction.2. No! It’s not changing speed or direction.3. -vf = 60 mph

vi = 0 mph t = 6 s-a = vf – vi

t-a = 60 – 0 mph = 10 m/s2

6 s

Graphing Velocity vs. Time

Constant acc. No acc. Increasing acc.

Exit TicketWhat is the unit of acceleration?

Solve these problems:1.A car is traveling at a velocity of 24 km/hr west

and increases to a speed of 50 km/hr west in 4 seconds. What is the car’s acceleration?

2.Jada is walking to the store at a velocity of 5 km/hr. She realizes that the store is closing in a few minutes. She accelerates to running at a rate of 15 km/hour in 2 seconds. What is her rate of acceleration?