2. Motion in one dimension 3. What is motion?Motion is when an
object changes position.How do you know that the race car moved? It
changed its position onthe track. 4. How can you tell something
haschanged position?Inorder to see if something has changed
position (motion) you need a reference point. For example, the
starting or finishing line of a racetrack.Click to edit Master text
stylesSecond levelThird levelFourth levelFifth level 5.
PositionIfsomething moves, it constantly changes position.When you
describe position, you refer to a point of reference/origin
(zero).When you have chosen your point of reference all positions
will be chosen relative to this point of origin.Position is the
place where an object is as observed from a point of reference. 6.
Frame of referencePoint of reference -3 m/3m to the left/ 3m W+5 m
/5m to the right/ 5m E X-axisLinear movement:when we need only one
axis.Y-axis (not used simultaneouslywith x-axis in grade 10) 7.
GPS24 satellitesAt least 4 sattelites will be visible at any time
from any pointEach sattelite sends a signal to GPS receiversThe
position of the receier can be determinedPosition is given in
latitude, longitude and height 8. Distance anddisplacement 9. What
is distance?Easy question!Distance is how far an object has
moved.We measure distance in METERS!Distance is the actual path
length that is taken. 10. Distance vs Displacement B
DistanceDisplacementA 11. What is displacement?Suppose a runner
jogs north to the 50-m mark and then turns around and runs back
south 30-m.Total distance is 80-m.Two directions - north and
south.Displacement is the distance and direction. 12.
DisplacementDisplacement is the change in position of the object.In
other words, a straight line.The magnitude of the displacement will
be smaller than or equal to the distance that was
covered.Displacement will be represented by x on the horisontal
line, and y on the vertical. 13. Calculating distance and
displacement x = xf xi = _m Lets try this: You move from your front
porch to your neighbours house 400 m away. Now calculate your
displacement. Moving from your front door (xi = 0 m ), and to your
neighbours house (xf = 400 m). x = xf xi = 400 0 = 400 m to the
right 14. Calculating distance and displacement IINow, you move
from your neighbours houseand move back towards your house, but
movebeyond and travel to the cafe 600 m from yourhome. Now
calculate your displacement fromthe moment you left home.Moving
from your front door (xi = 0 m ), and tothe cafe (xf = 600 m).x =
xf xi = 600 0 = 600 m to the left. 15. Scalars and vectorsScalars
are quantities that has only magnitude.Examples: distance time mass
volume, energy, work andpotential differenceVectors are quantities
that posesses bothmagnitude and direction.Examples: displacement
velocity acceleration force weight 16. Speed and velocity 17. What
is speed?Speedis the distance an object travels over time.Any
change over time is called a RATE.Speed is the rate at which
distance is traveled. 18. SPEED FORMULASpeed= Distance / Timev = x
/ tClick to edit Master text stylesSecond levelThird levelFourth
levelFifth level 19. Speed Example Suppose you ran 2 km in 10 min.
What is your rate? v = x / tv= 2 km /10 min.v= 0.2 km/min.Click to
edit Master text styles Remember the units!Second levelThird
levelFourth levelFifth level 20. Constant SpeedWhatdoes constant
mean?Ifyou are driving on the highway and you set your cruise
control, you are driving at a constant speed.Whatwould a constant
speed graph look like? 21. Constant Speed Graph 22. Do you always
go the same speed?No! Most of the time you are increasing speed,
decreasing speed, or stopping completely!Think about driving a car
or riding a bike!Click to edit Master text stylesSecond levelThird
levelFourth levelFifth level 23. What would a changing speed graph
looklike? 24. What is average speed?How do you find an
average?Averagespeed is the total distance traveled over the total
timev = xtotal / ttotal 25. What is Instantaneous speed?What does a
speedometer in a car do? It shows how fast a car is going at one
point in time or at one instant.Instantaneous speed is the speed at
a given point in time. 26. What is Velocity?Speed is how fast
something is moving.Velocity is how fast something is moving and in
what direction it is moving.Why is this important? Hurricanes
Airplanes 27. Speed or Velocity?Ifa car is going around a
racetrack, its speed may be constant (the same), but its velocity
is changing because it is changing direction. Click to edit Master
text styles Second level Third level Fourth level Fifth level 28.
Speed or Velocity?Escalatorshave the same speed (constant), but
have different velocities because they are going in different
directions. Click to edit Master text styles Second level Third
level Fourth level Fifth level 29. acceleration 30.
AccelerationWhen an objects velocity changes, it
accelerates.Acceleration shows the change in velocity during a
period of time.Acceleration = change in velocity / timea = v/t = vf
- vitf-tims-2 31. Acceleration IIMagnitudeis calculated using the
formula.The direction can be determined as long as motion is in one
dimension.v = increase, a in the same direction.v = decrease, a in
opposite direction. 32. Positive accelerationPositive values show
that the ais in the same direction as themotion. An increase in
v.Negative accelerationNegative values show that the a is in the
opposite direction fromthe motion. A decrease in v.Constant or
uniform accelerationWe only use constant acceleration. Because
wework with constant a, instantaneous and averageacceleration will
always be the same. This meanswe use the same formula to calculate
all threetypes of acceleraion. 33. Describing motion withdiagrams
34. What is a motion diagram? Click to edit Master text styles
Second level Third level Fourth level Fifth level 35. Images are
equal distances apart. Object occupies a single position. Object is
at rest. Constant velocity.Increase in distance between images.
Decrease in distance between images. Moving faster, accelerating.
Moving slower, decelerating. 36. Sketches and usesSketch a row of
dots to represent the object.Refer to previous slide to get the
spaces right.Draw a vector from each dot to show velocity.If
acceleration occurs, add one more vector to illustrate
acceleration. 37. The first dot is always labeled zero, and the
time elapsedBetween the dots are the same throughout.ABCD E0 1 2 34
tAB = tBC = tCD = tDE 38. Ticker timer and ticker tape Frequency:
number of dots that the timers hammer makes each second. Frequency
of 50 Hz. Period: the time it takes from dot to the next. 1/50 =
0,02s. Time interval: describes a collection of periods. Done in
1-dot, 5-dot or 10-dot intervals. 39. Determine the magnitude of
the avgvelocityYouwill need x and t for each specific interval.x =
determined by measuring spaces between intervals.t = determined by
multiplying the spaces with the period. 40. ExampleIn the first
tape, John is moving steadily while pulling aticker tape. Calculate
Johns average velocity. 41. Determining the avg accelerationYou
need four sets of information:vf, vi, tf and tivf vi = v for first
interval, and for last interval.tf ti = t where time is relative to
the time in the centre of the first and the last interval. 42.
Example Click to edit Master text styles Second level Third level
Fourth level Fifth levelIn the third tape, Sarah walks faster,
while pullinga ticker tape. Calculate Sarahs average acceleration.
43. Description of motionusing graphs 44. Calculus the abridged
editionSlope of the line (derivative) DisplacementVelocity
accelerationArea under the curve(integral) 45. Movement and
velocity 46. Positive velocity,positive direction from
rest.v(ms-1)t (s) 47. v(ms-1)t (s) 48. v(ms-1)t (s) 49. v(ms-1)t
(s) 50. v(ms-1)t (s) 51. v(ms-1)t (s) 52. Position-time graphs for
velocity 53. v(ms-1)t (s)x (m)t (s) 54. Movement with acceleration
55. v(ms-1) t (s)x (m)t (s)a(ms-2)t (s) 56. Finding velocityx + 8
mSlope == = +4 m st 2s 57. Instantaneous Velocity 58. Finding
accelerationv + 12 m sSlope === +6 m s 2t2s 59. Finding
displacementvv vo = atarea= lxb + bxhvox= vit + t(at) velocityx =
vt + at2t time 60. Equations of motion 61. Symbolsvi = initial
velocity in ms-1vf = final velocity in ms-1a = acceleration in
ms-2x or = displacement in mt = time in s 62. The formulas vf = vi
+atx = vit + at2 x = (vf2+ vi)t Vf2 = vi2 + 2ax 63.
PrinciplesWhenusing v, a and x, remember that they are vectors, so
take direction into account. Original direction of motion = +.If an
object starts from rest, vi = 0 m/sIf an object stops, vf = 0 m/sIf
chosen direction is +, then all v, and x substitutions are +. If
velocity increases, it is +.If velocity decreases, it is
-.Equations can only be used for motion with constant acceleration
in a straight line.Work in SI units.
