Transcript Speed measures how fast position changes

Take out your morning
article and begin
working silently.
When you finish, you
may take a book from
the bookshelf.
Agenda: Homework and
flash cards due Friday.
1. Explain the motion of
[figure a] in the picture.
Be sure to describe the
reference directions.
2. What is the reference point in this example?
7.P.1.2 Explain the effects of
balanced and unbalanced forces
acting on an object (including
friction, gravity and magnets)
Vocabulary Words
1. unbalanced force
2. balanced force
3. mass
4. friction
5. gravity
6. inertia
7. velocity
8. newtons
9. magnets
10. force
11. frame of reference
Balanced Force
Balance forces are two forces acting in opposite directions on an
object, and equal in size. Anytime there is a balanced force on an
object, the object stays still or continues moving continues at
the same speed and in the same direction.
Unbalanced Force
1. When two forces acting on an object are not equal in
size.
2. Unbalanced forces cause: a still object to move, an
object to speed up or slow down, a moving object to
stop, a moving object to change direction.
Magnet
An object that is surrounded by a magnetic field
and that has the property, either natural or
induced, of attracting iron or steel.
newton
(symbol: N) is the International System of Units
(SI) derived unit of force.
Notebook Title: Speed and
Motion
Testable Question: How can you measure
speed?
= Raise your hand to ask questions during
the lab
= stay positive and work as a team!
Motion
Definition: A change in position over time.
The ball moved from position 6 to position 3.
1
2
3
4
5
6
7
8
9
Speed
Definition: The rate of motion.
(how fast motion happens)
Speed is the measure of how fast something moves or the distance it
moves, in a given time.
Ball 1 moved 5 meters in 2 seconds.
(Slower speed)
Ball 2 moved 10 meters in 2 seconds.
(Faster speed)
Calculating Speed
speed = distance ÷ time
Units: meters/seconds (m/s)
miles/hour (mph)
kilometers/hour (km/h)
1.
If something travels 50 miles in one hour, what is its speed?
50 miles
1 hour
2.
If something travels 4 meters in one second, what is its speed?
4 meters
1 second
3.
= 50 miles per hour
= 4 meters per second = 4 m/s
If something travels 10 miles in two hours, what is its speed?
10 miles
2 hours
= 5 miles per hour
Question
CORNELL
What
is speed?
Notes
SYTLE
Speed is the measure of
How are speed and position
related? (hint: the library is 2
blocks away or the library is 5
minutes away)
how fast something moves
or the distance it moves in
a given amount of time.
(RATE of MOTION)
Speed and position both
deal with where an object is.
Question
Notes
Speed = distance divided
What is the
by time
formula used to
calculate speed? S=d/t
Practice Calculating Speed
1.
A man runs 200 m in 25 s. What is his speed?
2.
If you travel 100 m in 50 s, What is your speed?
200 m / 25 s = 8 meters per second
100 m / 50 s = 2 meters per second
3.
A women traveled 500 m in 20 s. What was her speed?
500 m / 20 s = 25 meters per second
4.
A wheelchair racer completes a 100 meter course in 20 seconds.
100 m / 20 s = 5 meters per second
Speed Triangles!
Flip over your note sheet to see how they work!
D
S
÷
T
x
1. Speed Distan
= _______ Time
_______
ce
D
S
÷
T
x
2. Distance =Spe
_______ Time
_______
ed
D
S
÷
T
x
3. Time =Distan
_______ Spe
_______ ce
ed
D
S
÷
T
x
4. Distance = 10 meters, Time
= 1 sec.
Speed =
10 m
÷
S
1s
x
5. Distance = 50 meters, Time =
10 sec.5 m/s
Speed =
50 meters
D
10 seconds
÷
S
T
x
6. Distance = 80 miles, Time =
2 hours40 m/h
Speed =
D
80 miles
÷
2 hours
S
T
x
7. Distance = 80 miles, Speed = 40
miles/hour
Time =
80 miles
40
miles/hour
x
÷
T
Sometimes, speed questions are
word problems.
Just set up your speed triangle!
1. Joe jogged for 1 hour. He ran 6 miles. What was
his speed in miles/hour?
6 miles / 1 hour = 6 m/h
2. Alex jogged for 2 hours. He ran 4 miles. What
was his speed in miles/hour?
4 miles / 2 hours= 2 m/h
3. Jose threw a ball. It traveled 50 meters in 5 seconds.
What was its speed in meters/second?
50 meters/ 5 seconds= 10 m/s
4. Ms. Reynolds was going 60 miles/hour on the
freeway. How far did she get after 1 hour?
60 miles x 1 hour = 60 miles
5. Ms. Wright was going 60 miles/hour on the freeway.
How far did she get after 2 hours?
60 miles x 2 hours = 120 miles
Can you calculate speed with
speed? 
Use speed triangles to solve practice problems.
The first person in each table to get all correct
will win a prize!
Work independently (silently).
Raise your hand if you have a question.
Be on task!
Exit Ticket
1.
Speed = ________ _________
2. A train travels for 3 hours. It goes 90 miles.
What was its speed?
3. A car is going 60 miles/hour. How far will it
go in half an hour?
4. A boat is going 25 miles/hour. How long will
it take for it to travel 100 miles?
5. 1 mile/minute = ___ miles/hour