bob & carol and alice all live in the same house. bob & carol go out to a movie, and when...
TRANSCRIPT
Bob & Carol and Alice all live in the same house. Bob & Carol go out to a movie, and when they return, Alice is lying dead on the floor in a puddle of water and glass. It’s obvious that Ted killed her but Ted is not prosecuted or severely punished. What happened?
1 Dimensional Kinematics
Bell Ringer Leave homework in the homework basket on the file
cabinet
Write down the objective!
Read the first page of the graphing skills packet
Underline the key points
Graphing Skill 1 What type of graph is it?
Graphing Skill 2: Labeling Axes
Graphing Skill 3: Scaling Axes
Step 1: What is the range of my data?
Graphing Skill 3: Scaling Axes
Step 2: What number do I count by?
Graphing Skill 3: Scaling Axes
Step 3: What does my scale look like?
Graphing Skill 4: Best-Fit Line or Curve
Walk this Way Lab Choose a timer and a recorder
Student 1: walk 20 record time, KEEP WALKING and record time at 40, 60, & 80
Everyone needs to have the data
Calculations: Speed=distance/time
Graphing: X=time
Y=position
Individual Conclusion Look at your graph. Was your line a straight
line? Why or why not? (A straight line means your pace was constant)
Which group member had the highest average speed? Any reason why?
Approximately how long would it take student 1 to travel 25 meters? (HINT: Use the formula to calculate average speed but solve for time)
Approximately how long would it take student 3 to travel 50 meters?
Linear MotionUnits 1 & 2
Bell Ringer 9/81. Write the objective
2. In the 2011 World Outdoor Championships, Allyson Felix earned silver in the 400.0 m race in 49.59 s and bronze in the 200.0 m race in 22.42 s. In which race did she run faster?
3. Write detailed directions explaining to someone how to arrive at Room 1070 from the main office.
3 ways to describe motion
1.Words in sentences
2.Mathematical equations
3.Graphs: show change in motion over time
Unit 1 Vocabulary Reference point: a base for comparison
Direction: up, down, positive, negative, etc…
Magnitude: size (always a number)
Scalar: magnitude, no direction
Vector: magnitude AND direction
Distance: separation between two objects
Displacement: straight line change in position of an object
Speed: distance/change in time
Velocity: displacement/change in time
Quick Check When you walked 20 meters during the lab,
what was your distance traveled? displacement?
40 meters?
60 meters?
80 meters?
Practice If you walk 5 blocks west and 3 blocks east,
what total distance have you traveled?
What is your displacement?
Practice If you walk 3 blocks north and 4 blocks west,
what total distance have you traveled?
What is your displacement?
Position v. Time Slope =
Velocity =
Y axis=position/distance (m)
X axis = time (s)
If the average velocity is the SAME for all time intervals, then the object moves at constant velocity
Slope = rise/run
X-axis? Y-axis? Slope? What type of motion does this graph represent?
Position v. Time Lab Rotation
Write the Station Number
5:35 per station
22:20 min total
After the rotation, a member of your group will be randomly called on to share your answers. Their answers will determine the grade for the ENTIRE group
Station #1
0
100
200
300
400
500
600
0 10 20 30 40 50
time (s)
po
sitio
n (
m)
Station #2
0
100
200
300
400
500
600
0 10 20 30 40 50
time (s)
po
sitio
n (
m)
Station #3
0
20
40
60
80
100
120
140
0 10 20 30 40 50
time (s)
po
sitio
n (
m)
Station #5
Significant FiguresSignificant figures are all the digits that are certain plus a digit that estimates the fraction of the smallest division of the measuring scales
Ruler A: 4.4 cm
Ruler B: 4.85 cm
How to Count Sig Figs1. Nonzero digits are always significant
Ex: 234 (3 sig figs) 1.236 (4 sig figs)
2. All zeros after the decimal point are significant
Ex: 526.7 (4 sig figs) 0.122344 (6 sig figs)
3. Zeros between other numbers are significant
Ex: 607 (3 sig figs) 1.206 (4 sig figs)
4. Zeros used as placeholders are NOT significant
Ex: 200 (1 sig fig) .00026 (2 sig figs)
PracticeState the number of significant digits in each
measurement:
1. 2804 m
2. 2.84 m
3. .0029 m
4. 4.6 x 105 m
5. .007060 kg
6. 75.00 mm
Addition & Subtraction
The number of decimal points in the answer must be the same as the number with the least number of decimal points
Example 1: 24.686m + 2.343 m +3.21 m =30.239m
3.21 has 2 decimal places, therefore your answer must have 2 decimal places
Final answer = 30.24m
Example 2: 32.596 cm-10.7 cm = 21.896 cm
10.7 has 1 decimal place, therefore your answer must have 1 decimal place
Final answer = 21.9 cm
Multiplication & DivisionThe number of significant figures in the answer must be the same as the number with the least number of significant figures
Example 1: 3.22 cm x 2.1 cm =6.762 cm
2.1 has 2 sig figs, therefore your answer has 2 sig figs
Final answer = 6.8 cm
Example 2: 36.5 m/3.414 s = 10.69 m/s
36.5 has 3 sig figs, therefore your answer has 3 sig figs
Final answer = 10.7 m/s
Speed v. VelocitySpeed and Velocity are
___________ the same thing
Speed has only______
Velocity has _______ and _______
Speed or Velocity? The pilot flew the airplane 500 mph
southeast
Tammy rode her bicycle 15 m/s
A car traveled 45 km/hr, west
A van went past the pedestrian at 70 mph
Calculating Speed A wheelchair racer finishes a 120 m race in
10 seconds. Calculate the average speed.
Speed = distance/change in time
V = D_ = 120 = 12 m/s
T 10
Calculating Velocity A wheelchair racer finishes a race 120 m to the
right of the starting line. It takes him 10 seconds to finish. Calculate the average velocity.
Velocity= displacement/change in time
V = D_ = 120 = +12 m/s or 12m/s right
T 10
Practice1. Michael Phelps completed the 100 meter
swim in 49.15 s. What was his speed during the race?
2. What is the speed in kilometers per hour of a train that travels 1,740 km in 60 hours?
3. What is the speed in kilometers per second?
Bell Ringer 9/101. Write the objective!
2. If you were to pay for gas by the mile, but you could choose to pay for your mileage measured by distance or displacement, which would you choose? Why?
3. What is the total displacement of a student who walks 3 blocks east, 2 blocks north, 1 block west, and then 2 blocks south?
4. A child walks 5.0 m north, 4.0 m east, and finally 2.0 m south. What is the magnitude of the resultant displacement of the child?
Whiteboard Races Make a box on your whiteboard to keep track
of points
You have 1 min for each question
Correct=1 point
Incorrect=0 points
No units=0 points
Incorrect sig figs = 0 points
1. Ms. Wu at rest.
1. Ms. Wu at rest.D
ista
nce
(m
)
Time (s)
1. Ms. Wu at rest.D
ista
nce
(m
)
Time (s)
2. Ms. Wu walks to the east.
Speed1. Determine the distance traveled
in 90 seconds by a car moving 30 m/s
2. Ms. Wu walks to the east.D
ista
nce
(m
)
Time (s)
3. Mr. Bhattacharya runs east.
3. Mr. Bhattacharya runs east.
Dis
tance
(m
)
Time (s)
4. Ms. Wu walks west.
Displacement Marty Graw is sightseeing in New
Orleans. She walks 3 km west, 2 km north, 4 km east and finally 2 km south. a. What is the total distance Matry Graw walked?b. What is Matry’s displacement?
Converting Units A glacier went as swiftly as 89
m per day down the valley. Find the velocity in m/s.
4. Ms. Wu walks west.D
ista
nce
(m
)
Time (s)
5. Mr. Kepple speeding up east.
5. Mr. Kepple speeding up east.
Dis
tance
(m
)
Time (s)
Speed & Velocity1. Does a speedometer tell you speed or
velocity? Why?
2. Find how long it would take to go 420 miles at 70 miles per hour
6. Mr. Bhattacharya slow downs east.
Dis
tance
(m
)
Time (s)
6. Mr. Bhattacharya slow downs east.
Otto Graph is the new soccer coach at Norland. He paces the side lines from A to B to C to D (in that order). a. What is the total distance Otto Graph walks?b. What is Otto’s displacement when he gets to point D?
Distance & Displacement
Ken Dahl drives 75 kilometers north to see Barbie when he realized he went too far and turned around and drove 13 kilometers south. a. What distance did Ken Dahl drive? b. What was Ken Dahl’s displacement from where he started?
7. Mr. Kepple jogs east then west.
7. Mr. Kepple jogs east then west.
Dis
tance
(m
)
Time (s)
In 1985, Matt Biondi set a record for the men’s 100 m freestyle event in swimming. It took him 49.17 s to swim the 50.0 m length of the pool and swim back. Assume that half of Biondi’s record time was spent traveling the length of the pool. What was his speed?
8. Everybody runs!
8. Everybody runs!D
ista
nce
(m
)
Time (s)
Displacement/Distance
1. What differentiates displacement and distance?
2. What is the displacement of a person who walks 40 meters north and then 20 meters south?
1. A high speed train in Japan travels a distance of 300 km in 3.60 x 10^3 seconds. What is the average speed of this train?
2. Jim’s dog chased a cat a distance of 30 feet for 12 seconds? What was the dog’s speed?
Speed & Velocity1. The cheetah, the fastest of land animals can
run a distance of 274 m in 8.65 s at its top speed. What is the cheetah’s top speed?
2. Find how long it would take to go 420 miles at 70 miles per hour
Deal or No Deal?
Game Rules Each slide will have an answer to the
numbered problems on your desk.
You and your partner must decide if the answer is correct or incorrect (deal or no deal)
Then you must explain WHY
3 min per question
Points awarded to all groups with the correct answer at the end of 3 min.
Problem #1 A. 1800 km/h
B. .27 hours
Problem #1c Flight A will arrive first
Problem #239.7 s
Problem #3a-b A. They’re moving with the same speed.
The pass each other a 5.5 hours
Problem #3c-d Car B is traveling faster
17.9 km/h
Problem #4a-b A. Just draw the diagram
B. .7m
Problem #4c-d .7m up
.7m up
Problem #5 A. Draw the route
B. 2600m
Problem #6 Yes an antelope with a 150.0-m lead can
outrun a cheetah
Problem #7 A. Person B
B. Person A
C. Person B
D. Person C
Describe the motion of the particle.
Displacement Sonny Day loves skiing. He skis from A to B to C to D
(in that order). What total distance does Sonny Day ski? b. What was his displacement from where he started?