DO NOW

AGENDA

Notes: Measuring motionCW #15 Joggers’ Journey 2

Week 13 Thursday Nov 5, 2015

DUE Friday Nov 6HW#13 Motion practice

1. Turn to LW#8 A Walk in the Park.2. Add a column to your Part b data table for “speed”3. Use your averages to Calculate your ACTUAL speeds for Part B Use the equation

Walking pace

distance (m) in 5 secondsTrial 1 trial 2 trial 3 average

Speed(Meters/sec)

slow

regular

fast

S = d/t

Notes # 5MEASURING MOTION

ESSENTIAL QUESTION:How can you determine how

fast an object is moving?

NOS RETAKEMust re-do HANGING WEIGHTS AND

BOUNCING SPHERICAL OBJECTS, on a new sheet of paper

• Must retake the test Tuesday 11/10At lunch

1. WHAT IS VELOCITY?

•The SPEED of an object

AND•The DIRECTION the object

is traveling

2. How is velocity different from speed?

The equation is still the same: s = d/t and v = d/t

The only difference is velocity includes DIRECTION OF THE MOTION

3. What are the units of measurement for velocity?

Velocity is a unit rate : unit of distance per unit of time

Velocity is expressed in whatever units were used for measuring distance and time

Examples: m/ sec

km/ hr

mi/ hr

WHAT IS THE VELOCITY OF THIS CAR?

START POINT END POINT20 m 100 m

TIME = 10 sec

VELOCITY = 8 m/sec NE

WHAT IS THE VELOCITY OF THIS CAR?

START POINT END POINT0 m 10 m

TIME = 20 sec

VELOCITY = .5 m/sec E

WHAT IS THE VELOCITY OF THIS CAR?

START POINT20 m

END POINT160 m

TIME = 7 sec

VELOCITY = 20 m/sec S

4. WHAT IS ACCELERATION?•The rate of change in VELOCITY

GIVEN THAT VELOCITY IS SPEED AND DIRECTION…

ACCELERATION OCCURS WHEN AN OBJECT

SPEEDS UP(goes faster)

SLOWS DOWN(goes slower)

CHANGES DIRECTION

Is it acceleration?

> Traveling at 60 km/hr on a straight road? nope

< Slowing down for a duck family crossing the road? yep

<Speeding up to get to class on time? yesiree

<Slowing down to turn a corner? absolutely

Turning a corner at a constant rate of speed?You betcha

5. How can you manipulate the speed equation?

Let’s try these

A cheetah runs 60 meters in 3 sec.

What is its average speed?

HMMM….WHAT AM I SOLVING FOR?

A cheetah runs 60 meters in 3 sec. What is its average speed?

HMMM….WHAT AM I SOLVING FOR?

A cheetah runs 60 meters in 3 sec. What is its average speed?

?60 m

3 sec÷

60 m ÷ 3 sec = 20 m/sec

D

S T

•A cockroach travels 12 meters across your bedroom floor and up to your bed at a speed of 3 meters/second. How long until you wake up screaming?

HMMM….WHAT AM I SOLVING FOR?

A cockroach travels 12 meters across your bedroom floor and up to your bed at a speed of 3 meters/second. How long until you wake up screaming?

HMMM….WHAT AM I SOLVING FOR?

A cockroach travels 12 meters across your bedroom floor and up to your bed at a speed of 3 meters/second. How long until you wake up screaming?

?

12 m ÷12 meters ÷ 3 meters/second = 4 seconds

3 m/s

D

S T

•A snake slithers toward a cute little mouse. In order to reach the mouse, he slithers 5 meters/second for 5 seconds. How far away is the mouse?

HMMM….WHAT AM I SOLVING FOR?

A snake slithers toward a cute little mouse. In order to catch the mouse, he slithers 5 meters/second for 5 seconds. How far away is the mouse?

HMMM….WHAT AM I SOLVING FOR?

A snake slithers toward a cute little mouse. In order to catch the mouse, he slithers 5 meters/second for 5 seconds. How far away is the mouse?

?

5 m/s 5 secx5 m/s x 5 sec = 25 m

D

S T

CHALLENGE QUESTION:

A fish is swimming in the lake at 25 km/hr. He swims for 30 minutes. to reach his home territory. How far away is his territory?

D = s x t

D = 25km/hr x .5 hr

D = 12.5 km

Write your own word problem where speed is the variable you are solving for. Remember to include the units of measurement for your distance and time

TOMORROWS DO NOWTURN TO NOTES #5 AND WRITE A WORD PROBLEM WHERE DISTANCE IS THE UNKNOWNAND ANOTHER WHERE TIME IS THE UNKNOWN