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MondayQuestion of the Day: What is the difference between
velocity and speed? Agenda:QuizestCornell NotesHomeworkDo Now: Grab
your personal scantronTurn in your Magnetism work packetClear your
deskHomework:(7) Reading Log 4: pg 313-315(8A) Problems pg 318
Trip to Stanford: Campus Tour and Mens Basketball Game!When:
Saturday, January 14thStanford vs. Colorado
To enter the lottery to win a ticket, email Ms. Gamm your name
and period by Monday January 9th
I will use excel to randomly pick 2 students Lab CorrectionsDue
Friday
Common lab misconceptions: changing voltage automatically
changes current add a coil to increase B-fieldMoving charges have E
& B fields DO NOT WRITE ON YOUR TESTWhen you are done with your
test:Make sure your test version (A or B?) is written on your
scantronBring your test & Scantron to meStart Reading Log pg
313-315
Linear Motion5Fastspeeddepends on distance and time average
speeduses total distance and total time
6Frame of Referencespeed is relativeF.o.R. is something to
compare speed toHow fast are you moving now?Earth is rotating at
1,000 mph
7Frame of ReferenceEarth is orbiting sun at 66,000 mphEverything
in universe is moving
8Frame of ReferenceSo, if you drive 55 mph, you are going 55mph
relative to the earthUniverse speed limit: speed of light 3 x 10 8
m/sIs car moving?
9VelocityScalar vs. Vectorscalar: measures only the amountex:
temperature, area, distance traveled vector: measures both amount
and directionvector: scalar and directionex: weightin which
direction is weight directed?10
Displacementspeed = distance / timevelocity = displacement /
timedistance: log of total miles traveleddisplacement: change in
positiondisplacement: distance from start to end
arrows mean they are vectors
distancedisplacement11Time to PracticeGo to pg.
31812TuesdayQuestion of the Day: What is the difference between
velocity and speed? Agenda:Check yourselfStart HomeworkHomeworkDo
Now: 1. Graph your Quizest score on your tracker!2. Check yourself
page 316-317Work in PairsWrite a short explanation for each
QuestionFirst 4 pairs to finish receives 3 tickets!Homework:(8B)
Problems pg 319-321 (14 & 15 Honors only) Quizest Corrections
& retakeCome in after school to do corrections (Due Friday)If
you do corrections, you receive the higher of the two scoresIf you
dont, you receive the averageRetake on Friday in room 308Tuesday
TutoringStop by if you need homework helpOr converting help Check
Yourself pg 316-317BABABABCBCABABBStart pg 319-321Remember
conversions!8. Convert minutes to hours9. Convert m to mi (1 mi =
1609 ft) and mach speed = 331 m/s10. Convert feet to miles (1 mi =
5280 ft) and seconds to hours12. Convert km to mHomework Answers pg
318Distance is same, but displacement is shorter on track B, thus B
is faster2A.) Vbicycle = 8 mph, Vwest = 21 mph, Veast = 39 mph2B.)
Vboy = 39 mph, Vbicycle = 47 mph, Vwest = 60 mph3.) Any straight
line motion in one direction4.) Any trip where you finish where you
started and moved some distance5A.) 12 blocks 5B.) 4 blocksHomework
Answers pg 3196.) Vavg = 6.25 m/s7A.) Vavg = 26 mph7B.) = 2 mph8.)
Vavg = 66 mph9.) t = 1.6 minutes10.) 6 mph over the speed limit11.)
saves 5.2 minutes12.) wait 210 s
Homework Answers pg 32013A.) Vavg = 38 mph, 13B.) = 27 mph 14.)
v = 21 m/s15.) d = 0.83 mi
Graphing RulesUse a ruler (straightedge)!Label your axes!(units
in parentheses)time is always below
Time (s)VariableUnit
Distance (m)Graphing Rules3.Title the graph!(Y vs. X)Distance
vs. TimeTime (s)Distance (m)Graphing Rules4.SCALE. Stretch out your
axes!Graphing Rules5. Use a Pencil!!6. Do not just connect the
dots!Line of best fit curve: smooth line: rulerthey might not touch
dots24Add scale consistency and line examples
Graphing RulesDrawing tangent linesdrawn at a pointbalance ruler
on curve perpendicular with normalDistance vs. TimeTime (s)Distance
(m)make it long enough to find the slopeAhh. Just
right!Graphing
26Add scale consistency and line examplesMoviesAnd now for a
short movie27Add scale consistency and line examplesEureka:
Inertia
28Eureka: Mass
29Eureka: Speed
30LabetteGraphing Motionpg. 30531Add scale consistency and line
examplesAccelerationacceleration the rate of change of velocity
final velocity initial velocityrefers to speeding up and slowing
down or
arrows mean
32ExampleA car moving at 20 m/s comes to a stop in four seconds.
What was the cars acceleration?Given:
Want:
33Example solve for acceleration
said negative five meters per second per secondnegative
acceleration meansslowing down34
35Accelerationyou feel speed when you accelerateThis includes
speeding up, slowing down and sharp turns at constant speed!All
three are accelerations
36Eureka: Acceleration I
37Speed vs. Time Graphslook at the slope
units are m/s/s=m/s2
acceleration!
same answer as example
38Speed vs. Time Graphs
So, to summarize the graphs: For distance vs. time:slope =
speedFor speed vs. time:slope = accelerationarea under line =
distance covered39Eureka: Acceleration II
40Freefallfreefall objects moving under only force of
gravity
terminal velocity when air resistance becomes equal to
gravity
due to gravity = g
g = 9.8 m/s2
41Freefalllets look at the motion of three objects
one dropped from restone thrown downwardsone thrown upwards
All of these motions are types offreefall!42Freefalllets look at
the motion of three objects
one dropped from restone thrown downwardsone thrown upwards
All of these motions are types offreefall!43Eureka: Gravity
44LabAcceleration due to Gravitypg. 31445Add scale consistency
and line examples
Putting it togetherLets use what we know about graphs to make
two more formulas.Lets look at the graph from ti to tf
46
Putting it togethereach time matches up with a velocityFirst
velocity is vi and last is vf
vi
vf47
Putting it togetherTo find distance: area under the linetwo
shapes: triangle and rectangle
vi
vf48
Putting it togetherd = area of rectangle + area of trianglearea
of rectanglearea of triangle
vi
vf
49Putting it together
we now have a connection between a and d50Putting it
togethersolve for t from first a equationsubstitute into second a
equationa little fancy algebra and
nice if you do not have t51Putting it togetheruse equation 1
only if acceleration is zerouse equations 2-4 only if constant
acceleration
52Putting it togethernotice there are no arrowsthey are still
all vectors
53Putting it togethervectors mean that direction is importantex.
positive for up, negative for down
54ExampleA spear is thrown down at 15 m/s from the top of a
bridge at a fish swimming along the surface below. If the bridge is
55 m above the water, how long does the fish have before it gets
stuck?Given:
Want:
why negative?
55Example
Which equation has vi, d, a and t?Eqn 3 works, butyou would need
quadratic (bleh!)
Eqn 2 would work if we had vf. Eqn 4 can get us vf!
56Example
First, eqn. 4
positive or negative?
57Example
solve for t in eqn 2.substitute vf into eqn 2.
58Check YourselfTurn to pg. 32159
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