grab a stop watch and take turns with your partner.- 5 minutes find out how long it takes you to...
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Grab a stop watch and take turns with your partner.- 5 minutes
Find out how long it takes you to walk the width of the space between the lab tables. (window to cabinets)
First walk stepping in each tile, use the stopwatch to time yourself. Record your time
Next walk stepping in every other tile, record your time. Last tip toe your way across the room..- record your
time.
Answer this question as a focus activity on the left side of your notebook:
What is the relationship between the distance you walk, the time it takes you to walk, and your walking speed?
When you are done get a calculator.
Motion – change in position relative to a reference point
Reference Point- place or object used for comparison to determine if something is in motion. Stationary objects such as trees or signs work best.
Motion
Use SI system
Distance- Meters
Time- Seconds
Formula : S= D/T
Add this to your new formula card
Unit- Meters Per Second
Velocity= Speed + Direction
Ex. 5 m/s North
Speed- rate of motion- The distance an object travels in a certain amount of time.
D
S T
1. What is the speed of a man walking 25 m in 15 s?
Distance= 25 meters
Time= 15 seconds
S= 25 m / 15s
S = 1.67 m/s
2. Armando rode his bike 1,500 meters to the store. He reached the store in 300 seconds. The store is North of his house. What is Armando’s velocity?
5 m/s North
3. What is the speed of a cheetah that runs 150 m in 5 sec.?
30 m/s
Practice Speed Calculations
1. How long will it take a man to walk 180 km, if he walks 3 km/hr?
Time ?
Distance= 180 km
Speed = 3 km/hr
Use your triangle!!
T= D/S T= 180 km/ 3 km/hr = 60 hours
2. How far will a cyclist go in 4 hours if she is going at a speed of 8 km/hr?
Distance?
Time= 4 hours
Speed= 8km/hr
Use your triangle!!
D= S*T D= 8 km/hr * 4hr = 32 km
Let’s mix it up a bit
Focus Activity- Make a paper air plane –decorate it if you want to… DO NOT THROW IT!!!- 5 minutes
Homework: Worksheet
Take a Flying High lab at read it over.
Wait for instructions.
Total Distance( TD) / Total Time (TT) - Add this to your formula card.
What was the average speed of a humming
bird’s 5 hour migration where it flew 100
m before sunrise, 300 m after
stopping to rest and then 100 more meters
after sunset?
Total Distance= 300m + 100m + 100m= 500m
Total Time= 5 hours
Ave. Speed = 500m/5hours = 100m/hr
Average Speed
Different types of speed
Instantaneous speed- The speed at which an object is moving at a particular instant.
Constant Speed- Speed doesn’t change ex. Cruise control
Flying High
Rules: Act appropriately in the hallway-
there are other classes in session. Do not throw your plane when
anyone is in the “flying zone” 1 partner will throw at a time, the
other partner is using the stopwatch to time your flight.
Record your results
Focus Activity: Speed Practice Problems 1. How long will it take a car to travel 420 km going a
speed of 60 km/hr?
2. How far will an athlete run in 2hrs, if he is running at a speed of 9 mi/hr?
3. How long will it take the Concorde SST to travel 14,400 km at a speed of 3600 km/hr?
Homework: Worksheet- Mini quiz on Speed Monday
Average Speed Problems
1. What was the average speed of a car during a road trip to Washington D.C., where the family drove for 50 miles before stopping for lunch, another 50 before stopping to re-fuel, and then 100 more miles before reaching their destination 4 hours later?
Interpreting
A straight diagonal line represents constant speed
A flat line represents no motion
The steeper the slope- the faster the speed
Acceleration
Rate at which velocity changes. 3 ways an object can accelerate:
-change direction – softball being hit by a bat
- increase speed – softball being thrown by the pitcher
- decrease speed- softball being caught by the catcher
Acceleration
Add this to your formula card
A= Final Velocity (Vf) – Initial Velocity (VI) Time
Unit= Unit for speed per unit of time Km/ Hr2 or Km/Hr/Sec
If unit of time from speed and unit of time are the same “square” it
To calculate the average acceleration of the airplane, you must first subtract the initial speed of 0 m/s from the final speed of 40 m/s. Then divide the change in speed by the time, 5 seconds.
A= 40m/s – 0 m/s 5s
A = 8m/s2
Graphing Acceleration
Speed vs. time
straight slanted line =
constant acceleration
Slope= Acceleration
Focus Activity: Grab a marble lab and read it over with your partner. DO NOT WRITE ON IT!!!!!
Homework: 9.3 Questions Show some Motion Project due 2/17 Keep collecting toilet paper and
paper towel rolls- aim for at least 20 each!
Enjoy your long weekend!!!!
Focus Activity: Use your formula cards to solve the following acceleration problems. H/W- 10.1 questions 1. Jeff is driving through the city at 45
mi/hr. The car in front of him slows down. It takes Jeff 10 seconds to slow down to 25 mi/hr. What is his acceleration?
Vf – Vi 25mi/hr – 45 mi/hr = - 2 mi/hr/sec
Time 10 sec
Josh takes 8 seconds to go from being stopped at a red light to 55 mi/hr. What is his acceleration?
Vf – Vi 55mi/hr – 0 mi/hr = - 6.89 mi/hr/sec
Time 8 sec