## Ms. Robak

# Email Info

If for any reason you will be absent from class and know in advance, please notify me by email so that I can ensure you receive the work that you need in order to stay with the class.

# Extra Help

# Grades

PHYSICS

PHACTS

TOP 5 FACTS:

PHYSICS OF TIME

**First in time**

The Egyptians were the first culture to become interested in timekeeping, building giant obelisks in 3500BC to act as giant sundials.

**Augustus**

In 8BC the Roman senate gave ruling emperor August Caesar his own month (August, if that wasn’t obvious…) and added an extra day to match his great uncle Julius Caesar’s month (yep, July!) on 31 days.

**Daylight**

Throughout World War II citizens in the United States kept their clocks one hour ahead of standard time to allow for longer working hours during daylight.

**Minuscule**

The world’s smallest atomic clock, built by the National Institute for Standards and Technology, is the size of a grain of rice and accurate to one second in 3,000 years.

**Samoa**

In May 2011 Samoa decided to move its clocks forward by one day to allow easier trade with Australia and New Zealand, after spending 119 years almost a day behind.

**Physics News**

**Projectile
motion is a form of
motion in which
an object or particle (called a
projectile) is
thrown near the earth's surface, and
it moves along a curved path under the
action of
gravity only.
The only force of significance that acts on the object is
gravity, which acts downward to cause a downward
acceleration. **
Projectile Motion is analyzed by applying kinematics of
motion with constant velocity horizontally and motion with
constant acceleration vertically.

**THIS WEEK (11/16 - 11/20):**

This week we will continue to look at projectile motion. We will recognize that the vertical and horizontal motions of a projectile are independent of each other. We will relate the height, time in the air, and initial vertical velocity of a projectile using its vertical motion, and then determine the range using the horizontal motion. We will see how the range of a projectile depends upon the acceleration due to gravity and upon both components of the initial velocity. The path a projectile takes, or its trajectory, is a curved path in the shape of a parabola.

**NEXT
WEEK (11/23 - 11/25):**

This week we will continue to study
projectile motion. We will still emphasize the independence
of the horizontal and vertical components of motion, and use
that concept to solve problems involving objects launched at
an angle and objects launched horizontally. In order to
solve any type of projectile problem, you need to solve for
time first. Since gravity only affects the vertical
component of motion, the horizontal component of
motion is constant, so when solving problems a_{x}
is zero.

**Upcoming
Tests/Quizzes/Labs**

☻**QUIZ -
Projectiles - Tuesday 11/17**

☻**LAB:
Projectile Lab: Due the week of 11/16 on your lab day!
(excludes period 3)**

☻**TEST-
Projectile Motion: Tuesday 11/24**