Physical Science Unit IV
Day 1 - 2 | Day 3 | Day 4 | Day 5 | Lab | Reading Assignment

This Unit's Process Standards: 3.2, 3.3, 4.3, 4.6, 4.8, 6.2, 6.3, 6.4 Content Standards: 2.1, 3.1 Instructional Technology Standards: 2.1, 4.1, 4.2, 4.3, 4.4

 Physics Newtonian physics Motion Reference point Speed Distance Time Average speed Velocity Vector Direction Graph Independent variable Dependent variable Slope

An Introduction To Physics

The Bayless High School Physical Science Class changes from a chemistry class to a physics class for the second semester. Physics is the study of the relationships between matter and energy.

 Most of what you will study this semester can be called Newtonian Physics. Named for Sir Issac Newton, it deals mainly with the interactions of visible objects around us. The laws of Newtonian Physics serve as the foundation for beginning physics students. As you learn more, you will see that physics explains the universe in mathematical terms.

 Mathematical calculations in physics are very formal.All problems should be worked as follows: Write the physics equation to be used to work the problem. Rewrite the equation with the known numbers plugged into the equation. Punch buttons on your calculator. Write the answer with its proper units. Circle the answer. This must be done to receive full credit for physics calculations.

Let's begin!

Motion: a change in position, measured by distance and time.

 What is a reference point?

Reference point: the point from which movement is determined.

To measure movement, some point must be considered as nonmoving.
Earth is the most common frame of reference, however:

• Earth rotates on its axis at almost 1100 miles/hour.
• Earth moves around the sun at over 68,000 miles/hour.
• The whole galaxy is rotating at about 490,000 miles/hour.
• Is there a universal frame of reference we can use to define the motions of all things?
Speed: the distance traveled by a moving object per unit of time.
To calculate speed, use the equation - Speed = distance / time

 Use the Factor Label Method for speed calculations.

 Speed Practice Problems: If the earth spins on its axis at 1100 miles/hour, what is the speed of the Earth's rotation in feet per second? The earth travels at 68,000 miles/hour as it moves around the sun. How many miles does the earth travel in one trip around the sun?

Average speed: the speed of moving objects is not always constant:

Average speed = total distance / total time
 Average Speed Practice Problem: You drive 200 miles in 3 hours before stopping for 30 minutes for lunch and gas. After lunch you travel 150 miles in an hour and a half. What was your average speed for the trip?

 Civil Engineer Velocity: speed in a given direction. Speed only gives distance and time. Velocity gives distance, time, and the direction of travel.

Velocity is known as a vector quantity because it has both speed and direction. Vectors can be use to graphically represent the mathematics of motion. The length of the line represents the quantity (speed) and the arrow indicates the direction.

The vector diagram here might represent the motion of an airplane. The first blue arrow shows the speed and heading of the plane. The second blue arrow shows the speed and direction the wind is blowing. Since the wind is changing the speed and direction of the plane, the two vectors are added, head to tail, to determine the actual speed and direction traveled. If the length of the blue vectors is drawn to scale, the length of the red vector will indicate the actual velocity of the plane.

 Concept Understanding: Use at least one paragraph to respond to this reference point situation. You are a passenger in a car stopped on the side of a hill. Out of the corner of your eye, you notice a tree on the side of the road begin to move forward. Work the following speed calculations: An airplane travels 500 miles in 2.5 hours. What is the speed of the plane? A toy car rolls down a ramp covering 24 feet in 6 seconds. What is its speed? A top fuel dragster covers the quarter mile in 4.5 seconds. What is its speed in miles per hour? A rifle bullet travels 6000 feet in 4 seconds. What is the speed of the bullet?

 With your table, discuss the following thought experiment. Be able to use one sentence to describe the boundary you have discovered surrounding your world. Your world has three dimensions; length, width, and height. Your experience in life involves motion in all three dimensions. Now, suppose you lived in a world with only two dimensions; length and width. Motion in this world can only be in those two dimensions. You have explored this world and found there is a un-crossable boundary surrounding your world.

Day 3

 How are speed and velocity different?

Computer Assignment 193:
This assignment must be completed by the end of class today to receive credit.
Scoring criteria

1. Search Google for Sir Isaac Newton. Find the following:
1. In what year was Newton born?
2. In what year did Newton die?
3. Find a picture of Newton and copy it.
2. Paste Newton's picture on the left side of a PowerPoint slide with this layout.
1. Title the slide "Newtonian Physics".
2. Type the year of Newton's birth and death on the right side of the slide.

3. There are many different ideas about the baseball pitch known as a "curveball". There are even people that will tell you it is an optical illusion! Explore the two websites below.

 The Exploratorium NASA

Make another PowerPoint slide with this layout.

• Drag and drop a picture from one of the websites on the slide.
• Write a short description on the slide about "Why curveballs curve".

Show the completed slides to your science facilitator.

Use this Java applet to experiment with a curveball.

Day 4

 What does the slope of the line on a distance-time graph represent?

Distance - Time Graph:

Time is the independent variable and always plotted on the horizontal axis.
Distance is the dependent variable and always plotted on the vertical axis.
A graph of constant speed will always be a straight line.
The slope of this line indicates the speed.
Review the seven steps of graphing.
View an example of a Distance/Time Graph made with PowerPoint.
• This graph represents the motion of a person. Can you describe what the person did?
Computer Assignment 194:
This assignment must be turned in by the end of class today to receive credit.
Scoring criteria
1. Use PowerPoint to make a graph of this person's motion:

A person walks 100 meters in 50 seconds, stops to rest for 30 seconds,
then runs back to the starting point in 15 seconds.

• Insert this grid on a blank PowerPoint page.
• Review this graph scoring rubric. Keep these criteria in mind as you use PowerPoint tools to complete the graph.
• Calculate the average speed of this person. Type the answer below the graph.
• Show the graph to your science facilitator when finished.

Physical Science

Portfolio assignment 192, optional assignment #3. These answers are rounded off:

1. 130 kg
2. 160 kg
3. 360 kg
4. 600 kg

A reference point is the point assumed to be unmoving by which motion is described.

Velocity describes direction while speed does not.

The slope of the line on a distance-time graph represents speed.