Name:_________________________
Topic: Motion, Speed, Velocity, and Acceleration
SPEED and VELOCITY
Today’s Standard(s):
S8P3. Students will investigate relationship between force, mass, and the motion of objects.
a. Determine the relationship between velocity and acceleration.
Catalyst
“How fast is that car going?” is an imprecise question that has two scientific answers. You could
respond with the car’s speed or the car’s velocity.
What’s the difference between speed and velocity? See if you can find out by watching this
music video “Speed and Velocity” by They Might Be Giants. (URL: http://vimeo.com/5395097)
1. What’s the difference between speed and velocity?
2. What units could we use to measure how fast something is moving?
Formula for speed (and velocity): **Velocity is a _______because it REQUIRES a _______!!!**
Units for Speed: **Speed is a ____________, which means is does NOT require a direction!**
Units for Velocity:
(Have you heard that terrible singer guy? His video is online at:
https://www.youtube.com/watch?v=4CWlNoNpXCc . Don’t ask me why anyone would ever
choose to listen to it…)
Catalyst Part 2: What does “miles per hour” really mean?
CALCULATORS AT THE READY!
What does it mean if a person is crawling 1 kilometer per hour (1
km/h)?
In one hour…
In one minute…
What does it mean if a car is moving at 60 kilometers per hour (60 km/h)?
In one hour…
In one minute…
What does it mean if the Earth’s plates are drifting at 2 centimeters per year (2 cm/year)?
In one year…
In one decade (____ years)…
In one century (_____ years)
How fast does Usain Bolt run? Watch the video to find out:
https://www.youtube.com/watch?v=2O7K-8G2nwU
How about Para-Olympian Jason Smyth? Watch the video to find out:
https://www.youtube.com/watch?v=LZovT5yZJdQ
Speed vs. Velocity
Speed
Velocity
•
•
•
• Ex.
•
•
Circle all of the speeds:
50 m/s
65 km/h forward
175 mm/s
•
•
•
• Ex.
•
•
17 cm/hr north
12 mm/year
0.5 m/s to the left
750 km/s toward the moon
2 cm/year
Discussion Questions
1. The police are tracking an escaped prisoner. Would it be more helpful to know her speed or
her velocity? WHY?
2. Your parents don’t trust your older brother with his car. They install a device into the car to
text them whenever he goes faster than 70 miles per hour. Does this device need to monitor
his speed or his velocity? WHY?
3. Think of an example in your life where you care how fast something is moving (a bus, a bike,
a roller coaster, etc). Do you really care about the object’s speed or its velocity? WHY?
Acceleration: What is it??
Today’s Standard(s):
S8P3. Students will investigate relationship between force, mass, and the motion of objects.
a. Determine the relationship between velocity and acceleration.
Catalyst
Velocity vs Time
10 m/s
5 m/s
0 m/s
0s
5s
-5 m/s
-10 m/s
1. During part I, the object is:
A. Accelerating
B. Decelerating
C. Neither.
2. During part II, the object is:
A. Accelerating
B. Decelerating
C. Neither.
3. During part III, the object is:
A. Accelerating
B. Decelerating
C. Neither.
Explain how you know:
Explain how you know:
Explain how you know:
Moving On: Check out this video on acceleration:
http://www.youtube.com/watch?v=e5Gl2LLLAGo
10 s
So…What IS Acceleration?
When people are reviewing sports cars, they often talk about the time it takes
the car to go “0-60.”
What does that mean?
In scientific terms, “0-60” time is just a measure of the car’s
________________________! They are timing how long it takes the car’s
speed to increase from _____________ to ___________.
Acceleration is how quickly an object changes its _____________________ (SPEED and DIRECTION).
______________________________________ is how quickly an object is decreasing its speed.
To CALCULATE Acceleration, use the formula:
a=
∆=
USE THE TRIANGLE!!!
D=
R=
T=
What units would we use with the metric system?
Which of the following describes acceleration?
SO…
10 cm
10cm/second/minute
10 cm/second
10 cm/second/second
D=
R=
T=
Some examples of acceleration:
Some examples of deceleration:
Some non-examples of acceleration:
When you ______________ you are actually accelerating! This is because acceleration happens whenever
your ________________ changes.
Speed, Velocity, and Acceleration
Exit Ticket
Today’s Standard(s):
S8P3. Students will investigate relationship between force, mass, and the motion of objects.
a. Determine the relationship between velocity and acceleration.
1.
Give an example of a speed that a car might be traveling.
Make sure that your answer includes correct units.
2.
Give an example of a velocity that a person might be walking.
Make sure that your answer includes correct units.
3. What is the difference between speed and velocity? Please use scientific vocabulary in your answer.
For each of the following situations, decide if it is an example of acceleration, deceleration, or
neither.
4. Constant speed of 5 m/s
A. Acceleration
C. Neither
B. Deceleration
5. Change of speed from +5 m/s to +2 m/s.
A. Acceleration
B. Deceleration
C. Neither
6. Velocity of 5 m/s forward to 5 m/s to the right.
A. Acceleration
B. Deceleration
C. Neither
7. Over 12 seconds, you go from standing still to running quickly. The best metric unit to
measure the change in your velocity is:
A. mph
B. km/h
C. m/s/s
D. m/s