Monday, January 5, 2015
• Objective: Students will
investigate the relationship
between displacement and
rotational motion of
objects.
• Homework: None!
Welcome Back!

•
1.
a.
b.
c.
d.
2.
f.
g.
h.
j.
Bellringer Answer Choices:
0.000 AU
0.010 AU
0.020 AU
0.040 AU
1.010 AU
1.990 AU
2.000 AU
2.010 AU
Think & Write
• What does it mean for something to revolve?
• What does it mean for something to rotate?
• Give an example of each.
Turn & Talk
• Share what you wrote with your neighbor. Do
you both agree? Disagree?
• Be prepared to share out.
Rotational Motion
• Move to groups.
• Read the passage at the top of your handout.
Work through the first short answer question,
and the investigation, as written.
• When you are done, let Ms. Kline know,
before you move on.
Unit Circle
• Radian: the angle for
which the length of a
circular arc is equal to
the radius of the circle.
• 2 pi radians = 3600
• 1 radian = 57.30
• 1 revolution = 2 pi
radians = circumference
of the circle
Unit Circle
• If we cant to know an
arc length, we can use
the following equation:
s  r
s  arclength
 (radians)
r  radius
circumference  2r
Back to Your Model
• Convert your value into radians.
• Complete the practice problems on the
worksheet.
3-2-1
• What are 3 things you learned about
rotational motion?
• What are 2 things you want to know?
• What is 1 question you have about the
process, or in general?
Tuesday, January 6, 2015
•
3.
a.
b.
c.
d.
4.
f.
g.
Bellringer Answer Choices:
Both points are unstable, and L1 is farther away from the Sun.
Both points are unstable, and L2 is farther away from the Earth.
Both points are unstable and are on opposite sides of the Earth.
Both points are stable, and L2 is farther away from the sun.
less than the distance from the Sun to Mercury.
between the distance from the Sun to Venus and the distance from
the Sun to Earth.
h. greater than the distance from the Sun to Mars.
j. between 1 AU and the distance from the Sun to Mars.
Homework:
Reading Due
Thursday!
• Objective: Students practice calculating arc length and displacement
in practice problems.
Reading Questions
• Answer the following questions in complete
sentences (2-3 per question):
– How is the planet mentioned in the article like
Earth?
– Could humans live on this planet? Why or why
not?
– How is this planet similar and different from other
Earth-like planets that have been found?
Back to Yesterday
• What is a radian?
• How is a radian related to degrees? To the unit
circle?
Unit Circle
• Radian: the angle for
which the length of a
circular arc is equal to
the radius of the circle.
• 2 pi radians = 3600
• 1 radian = 57.30
• 1 revolution = 2 pi
radians = circumference
of the circle
Converting Between Degrees
and Radians
360
Radians    Degrees : radians *
 deg rees
2
deg rees
Degrees    Radians :
* 2  radians
360
Unit Circle
• If we want to know an
arc length, we can use
the following equation:
s  r
s  arclength
 (radians)
r  radius
circumference  2r
Unit Circle
• Angle measures are
given relative to a
reference line. That line
is usually at 00, or 0
radians.
– Can be changed!
• Position is given in
radians
Unit Circle
• Counterclockwise
rotation = positive
motion (positive
velocity)
• Clockwise rotation =
negative motion
(negative velocity)