Physical Science Week 22
Day 1 | Day 2 | Day 3 | Lab 1 | Lab 2 | Reading Assignment

This Week's	Process Standards: 1.3, 3.3, 3.5, 4.2, 6.1, 6.4 Content Standards: 2.1, 2.2 Instructional Technology Standards: 2.1, 4.1, 4.2, 4.4
	Teaching Standards: All Assessment Standards: All Content Standards: A, B, D, E, F, G Program Standards: All System Standards: All

Force Friction Sliding friction Rolling friction Fluid friction	Aristotle Newton Balanced forces Unbalanced forces	Newton's 3 Laws of Motion Gravity Free fall Acceleration of gravity Terminal velocity

Force: any push or pull.

Friction is not always bad. Discuss this with your table. Think of two examples of when friction is good. Tell your science facilitator when you have them. Ask your teacher for a ball. Go into the hall and roll (do not throw) the ball down the hall. Carefully observe the actions of the ball. Do your observations support Aristotle or Newton? Be able to verbally explain the reasoning for your answer. With your table, demonstrate each of these for your science facilitator. Use any book from the shelf under the window. If you need something other than a book, ask for it. Move a book across a table in a way that demonstrates sliding friction. Move a book across a table in a way that demonstrates rolling friction.

Day 2

What two balanced forces are acting on you right now?

Most of the time an object is being acted on by more than one force.

Balanced forces:
• Forces that are opposite in direction and equal in size.
• Balanced forces cause no change in motion.
Unbalanced forces:
• Forces that are not opposite and equal.
• Unbalanced forces always cause a change in motion.
• A very graphic example of unbalanced forces causing motion.

(Newton's laws - 5 min)     #2 Questions

Newton's Three Laws of Motion explain all aspects of motion.

(rockets - 6 min)     #3 Questions

What forces cause a gyroscopeto work? What makes a rocket enginework?

Computer Assignment 222:
This assignment must be turned in by the end of class today to receive credit.
Scoring criteria

Make a PowerPoint slide for each of the following points:

1. Using this slide layout type "Newton's Three Laws of Motion"
    
   
2. Using WordArt on this slide layout, add "Motion Requires Unbalanced Forces".
3. Add 3-D to the WordArt on the slide above.
4. Make a slide with this layout for each of the following.

   Put a picture representing the subject on the left of each slide.
   On the right of each slide, indicate which of Newton's Laws applies.
    
   A. The space shuttle leaving the launch pad.
    
   B. A bowling ball moving down the alley or striking the pens.
    
   C. A snow skier moving downhill.
    
   D. The Golden Gate Bridge.

5. Using WordArt on this layout, title the slide "Newton's Second Law".

   Use factor label to work the problem below on the slide under the title.
   Use regular text for the problem.

The Problem:

What force (in Newtons) is needed to accelerate a one ton truck at a rate of 10 m/s2?

2000 pounds = one ton 454 grams = one pound 1000 grams = one kilogram

Show the completed slides to your science facilitator when finished.

Day 3

Why does a hammer fall faster than a feather?

Gravity: the force of attraction between all objects in the universe.

• Gravity is the weakest of the known natural forces, only becoming obvious when massive objects like stars and planets are involved.
• Gravitational radiation is only 1 X 10 ^-40 times as strong as electromagnetic radiation.

(skateboards - 3 min)     #4 Questions

Free fall - an object falling under the influence of gravity.

Near the surface of the earth all objects are accelerated by gravity at a rate of 9.8 m/s/s. Calculations can be simplified by rounding to 10 m/s2.

Drop some objectson Earth.

Drop some objects on Earth, Moon, and Mars.

Terminal velocity: the point at which air resistance offsets the weight of a falling object, stopping its acceleration.

The object continues to fall but does not accelerate.

A skydiver decreases terminal velocity with a parachute.

Concept Understanding: Read this experiment by Galileo Galilei. How did Galileo's idea of acceleration differ from Aristotle's? Using only one short paragraph, describe Galileo's acceleration experiment. You have to know physics to do tricks on a skateboard. How did skateboarding begin? What is a trick known as the "ollie"? What keeps the skateboard against the feet when doing an "ollie"?

Apply The Scientific Method 1. The Question: How many drops of water will fit on the head of a penny? 2. The Hypothesis: Make a prediction. 3. The Experiment: Test your hypothesis. Equipment List: 1 penny 2 dropper pipets water soapy water paper towels The Data: How many drops actually fit on the head of a penny? ___________ (Trial 1) Retest: Dry your penny and test again. Scientists often perform many trials to prevent errors. Trial 2 _________ Trial 3 _________ Trial 4 ________ Calculations: Find the average of your trials. 4. Draw Conclusions: What is the average number of drops that can fit on a penny? _______   Extension: Would the number of drops be different for soapy water? Form a hypothesis and test it. Analysis: Answer the question: Does the kind of water make a difference? Does soapy water behave differently from non soapy water? Suggest a reason for your observations. Do you think other elements, such as salt or sugar or oil would affect the number of drops that could fit on a penny? How would you test this hypothesis.

Research Links:

• Some History of Newton's Laws - Canterbury Christ Church University College, UK
• Orbits and Tides - Astronomy Notes Homepage
• Free-Fall - Honolulu Community College
• Free Body Diagrams - University of Guelph