Motion

1
Motion

• Speed, Velocity, and Acceleration

2
What is Motion?

• How would you describe motion?
• Okay, now try it again this time without using
  the word Move Movement or Motion ?.
• Quick Write (2 min)

3
Air Trolleys

• Air Trolley Construction
• Explore movement and think about ways to describe
  it.
• As a group decide on a way to measure the
  movement you observe and then record your
  measurement, including drawings.
• What are some important things to consider when
  measuring the movement?

4

• Motion occurs when there is a change in position
  (location) of an object with respect to a
  starting reference point.

5
Position

• Position is the location of an object .
• The change in position is determined by the
  distance and direction of an objects change in
  position from the starting point.
• Position is represented by the variable x. x
  marks the spot!

6
Reference Point

• The object or point from which movement is
  determined
• Movement is relative to an object that appears
  stationary
• Earth is the most common frame of reference/
  reference point

7
Questions

• What is the frame of reference for the sunset?
• What is the most common frame of reference?

8

• Day 2

9
Giving Directions

• We will blindfold one person.
• Now I will draw a simple picture for the rest of
  the class to see.
• A non-blindfolded person will give directions for
  the blindfolded person to recreate the original
  image on the board.
• You try it!
• Did you create a reference point?
• Why are good directions so important?

10
Direction

• Direction is the line, or path along which
  something is moving, pointing or aiming.
  Direction is measured using a reference point
  with terms such as up, down, left, right,
  forward, backward, toward, away from, north,
  south, east or west.

11
Giving Directions
Segment Distance (m) Direction
A 7 East
B 6 North
C 2 West
D Less than a meter Up
What was the total distance traveled? What was
the displacement?
12
What is Displacement?

• Displacement is the distance between the initial
  position (reference point) and the final position
  taking the SHORTEST route.

13
What is the difference in Distance and
Displacement?

• Distance total ground covered, regardless of
  direction
• Displacement overall change final position
  initial position shortest route
• If you walk 5 blocks north and 3 blocks south,
  what total distance have you traveled?
• What is your displacement?

14

• 1. What is the displacement of the cross-country
  team if they begin at the school, run 10 miles
  and finish back at the school?
• 2. What is the distance and the displacement of
  the race car drivers in the Indy 500?

15
You try it

• A squirrel climbs 12 meters up a tree and then
  7.5 meters back down the tree.
• What is the total distance that the squirrel
  traveled?
• What is the displacement of the squirrel?

16

• During basketball practice Marcus runs the
  length of the basketball court 10 times. (the
  length of a basketball court is 94ft)
• What is Marcus total distance traveled?
• What is Marcus total displacement?
• 2) Liam leaves a history classroom and walks 10
  meters north to a drinking fountain. Then he
  turns and walks 30 meters south to an art
  classroom.
• What is Liam's total displacement from the
  history classroom to the art classroom?
• What is Liams total distance traveled?

17
Challenge Question

• Seth walks 5 meters north, then 4 meters east,
  and finally 2 meters south.
• What total distance did he travel?
• What is Seths displacement?

18

• Day 3

19

• Find Mrs. Clarks average speed walking across
  the classroom.
• THINK What do you need?

20
SPEED!

• Motion can also be described by the relationship
  between distance an object travels and the period
  of time it travels. This measurement if motion is
  a rate.
• Speed is a measure of how fast something moves a
  particular distance (for example meters) over a
  given amount of time (for example, seconds).

21
Speed vs. Velocity
22
Question

• When can you determine how fast you are going in
  a jet plane?

23
Speed

• The units for speed
• meters/second (m/sec)
• kilometers/hour (km/hr)
• Speed that does not change is constant speed.

24
Average speed

• Total distance divided by the total time
• Formula
• total distance
• total time

25
To find average speed, find total distance and
divide by total time, dont average two speeds!

• Harli jogs 400 meters in 120 seconds, then jogs
  200 more meters in 40 seconds. What is Harlis
  average speed?

26
Practice

• 1) Brendon runs 25 meters in 4.3 seconds, then
  runs another 20 meters in 3.3 seconds, but gets
  tired and runs 15 more meters in 4.4 seconds.
  What is Brendons average speed?
• 2) I walk 20 blocks north, then 15 blocks east,
  then 20 blocks south, all in 1 hour total. What
  is my average speed?

27
You try it!

• Kayla jogs 400 meters in 120 seconds, then jogs
  200 more meters in 40 seconds. What is Kaylas
  average speed?

28
Questions

• What is motion?
• What is speed? How is it calculated?
• What is average speed?

29
Velocity

• Speed in a given direction
• Velocities in the same direction combine by
  adding
• Velocities in different directions combine by
  subtracting

30
Interesting fact

• Rockets are launched in the same direction of the
  earths rotation to get an extra boost of 1800
  km/hr to its speed

31
Discussion Questions

• See if you can come to a consensus on answers to
  these questions
• A yellow car is heading East at 100 km/h and a
  red car is going North at 100 km/h. Do they have
  the same speed? Do they have the same velocity?
• A 16-lb bowling ball in a bowling alley in Del
  Mar heads due north at 10 m/s. At the same time,
  a purple 8-lb ball heads due north at 10 m/s in
  an alley in La Jolla. Do they have the same
  velocity?

32
Welcome to High School Scalars vs. Vectors

• Scalars are quantities that are fully described
  by a magnitude (or numerical value) alone.
• Vectors are quantities that are fully described
  by both a magnitude and a direction.

33

• Exit Slip
• What is the main difference between speed and
  velocity?

34

• Day 5

35
DO Now Questions

• How is velocity different from speed?
• Which two factors determine an objects velocity?

36
Acceleration

• The change in velocity
• Acceleration is measured in m/sec/sec or m/sec2
• Formula is
• (final velocity - original velocity)/time

37
Deceleration vs. Acceleration

• A decrease in velocity is negative acceleration
• A distance-time graph for acceleration is always
  a curve

38
Centripetal Acceleration

• Acceleration directed toward the center of
  circular path

39
Questions

• What is acceleration?
• What is the shape of a distance-time graph for
  acceleration?
• What is centripetal acceleration?

40
Momentum

• Momentum is equal to the mass of an object times
  its velocity
• momentum mass x velocity

41
Conserving Momentum

• The law of conservation of momentum states that
  the total momentum is NOT lost, only transferred

42
Questions

• What is momentum?
• What happens to momentum as the mass of a moving
  object increases?
• What is the formula for momentum?
• What is the law of conservation of momentum?