Osmosis Video Viewed in Class

Scientific Method Video

Follow the link below to find the Brainpop video we viewed in class. There are a few activities you can do as well.

https://www.brainpop.com/science/scientificinquiry/scientificmethod/

CHAPTER 5 TEST DATE

CLASSES 7A, 7C, 7D, and 7E WILL NOW HAVE THEIR TEST ON FRIDAY DECEMBER 11th 2015

CLASS 7B WILL HAVE THEIR TEST ON MONDAY DECEMEBER 14TH 2015

Additional Online Review

Some additional online quizzes...

You can complete these quizzes to help you study. Remember that completing the quizzes does not replace studying from your notes!

You may ignore concepts from section 5.2 if you come across them in the chapter review.

Section 5.1 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_05_1mM3MX.htm

 Chapter 5 Review Quiz

http://wps.pearsoned.ca/ca_school_ontarioscience_7-8/102/26140/6692002.cw/content/index.html

Chapter 5 Matching Terms

https://sciencesource.pearsoncanada.ca/resources/gr7_matchquiz_ch05/

Chapter 5 Labeling Practice

https://sciencesource.pearsoncanada.ca/resources/gr7_labelquiz_ch05/

5.1 Crossword

https://sciencesource.pearsoncanada.ca/puzzles/puzzle_05_1/

Chapter 5 Test Study Guide

Review the following terms and concepts to help you prepare for the chapter 5 test.

Please make use of your classroom notes, the textbook, as well as your completed worksheets from your package.

Remember, this test only covers section 5.1 in the textbook.

□  arch

□  beam

□  box beam

□  cantilever

□  centre of gravity

□  column

□  corrugated cardboard

□  corrugated metal

□  ergonomics

□  failure

□  fatigue

□  girder

□  I-beam

□  product recall

□  stability

□  truss

□  structural components

□  structural failure

□  structural fatigue

□  structural stress

1. What are the strongest structural shapes? (p. 131)

2. Become familiar with the 8 structural components on page 132.

3. Review how to determine the centre of gravity of a structure.

4. What makes a structure stable? (p. 133-134) and review the package worksheets.

5. Review product recalls. (p. 136)

Section 5.1 Notes

Good design, materials, and construction make structures stable and strong

·         Stability and strength depends on a structure’s material as well as the fasteners used (bolts, welds, wire, thread, glue, etc.)

·         

Stability: the ability of a structure to maintain or resume its position when an external force has been applied to it.

Structural Strength

·         Some structures have stood for thousands of years e. g., the Coliseum in Rome, the Pyramids in Egypt

Structural Shapes

·         Some structural strength comes from the shapes used in its design

·         Triangles are stronger than squares and rectangles

·         Triangular prisms are stronger than square and rectangular prisms

Structural Components

·         Arches, beams and columns are common structural components that are used often because they can add strength and are attractive

·         The components can be used alone or in combination e.g., arches and columns

Structural Materials

·         It is important to choose appropriate materials when designing and building structures; designers should consider strength, attractiveness, cost, etc.

Centre of Gravity

·         Centre of gravity: the point at which a body’s mass is concentrated – the body is equally balanced in all directions at this point

 For example, when you balance a ruler on your finger, the centre of gravity is the middle of the ruler because each side of the ruler is symmetrical 

·         Every structure has a centre of gravity; the location of the centre of gravity helps determine how stable the structure is

For example, a stool is a stable structure; however when a person sits on the stool, the centre of gravity is higher so the stool is more likely to tip over

Stability

·         Stability depends on materials, construction techniques and centre of gravity

      E.g., a table can have a high centre of gravity, but it can be stable if it has four legs far apart

·         Form can also affect stability; a solid structure with a high centre of gravity may be less stable than a frame is

·         Some structures are designed to be unstable; e.g., front ends of cars are meant to collapse easily in a collision

When Things Go Wrong

Structural Stress and Fatigue

·         Poorly built structures may not be able to withstand forces

·         Large internal and external forces may weaken the structure

·         This can result in structural stress

·         A bend in a shelf is an example of this stress; the shelf may go back to its original shape when the load is removed

·         Permanent changes occur when the shelf cannot withstand the stress; e.g., cracking. This is called structural fatigue.

Structural Failure

·         Ignoring structural fatigue can lead to structural failure; this is the breakdown of a structure due to the internal and external forces acting on it

·         Structures often show signs of structural fatigue by bending and cracking before finally failing and collapsing.

Product Recalls

·         Public recall of seriously flawed products sold to consumers by manufacturers

·         Examples:

·        high levels of paint in children’s toys

·        choking hazards in products for children

·        overheating batteries, poor safety features

·        cars with faulty parts or design

Centre of Gravity Videos

Please Bring in 2 Nickels!

We are doing an activity this week that requires 2 nickels (five cent coins) that you will be able to bring home afterwards.

Jib Building Worksheets

The package of planning and reflection worksheets are due the day following your jib testing date. Most groups have completed testing and already submitted their package for assessment.

If you have not submitted your package, please do do tomorrow.

Bangladesh Building Challenge

At this point you are working on

STEP 1 - Initiating and Planning and STEP 2 - Investigate 


For STEP 1 - Complete the Initiating and Planning section on the back of the Bangladesh Building Challenge worksheet. You will need to describe the situation and identify the problem that needs to be solved. A diagram is recommended.

For STEP 2 - You will have started working on this step in the computer lab this week. You are to brainstorm 4 different tower crane jib designs. Each design should be sketched in the space provide on the "Investigate" worksheet you received in class.

You should use 2 different colours to identify where the internal forces of tension and compression are in action on your sketch.

BOTH OF THESE SHEETS ARE TO BE COMPLETED FOR YOUR NEXT SCIENCE CLASS!

Don't Forget!

Review the reasons why the Tacoma Narrows Bridge collapsed!

I hope you all have already started to review the material! :)

Designing for Safety Worksheets Answers

Designing for Safety

In this section, you will learn about some of the way in which designers plan safety into structures and the factors they consider when designing and monitoring them.

No one can design a structure to be 100% failure proof. The materials may wear down over time. A person may use it incorrectly and break it. Unexpected forces might come into play

Engineers use the techniques of risk management to reduce the risk of failure as much as possible.

They deal with known risks in one of three ways:

Ignore the risk

Avoid the risk

Design for the risk

When a risk unlikely to occur, it can be ignored. E.g., an elephant sitting on a classroom chair.

Building a bridge with no supports in the water is a way to avoid the risk of boats colliding with the bridge supports.

When designers design for risk they often over-compensate for the various risks. They often make the structure stronger than really needs to be; e.g., stronger bridge supports in the water in case of a boat collision.

They also build in back-up and warning systems that may use sensors.

Designing for Loads

When designing a structure, the designers must calculate the load it will support. They design the chair to support more than itself plus the biggest occasional load. Some structures have warning notices about the maximum load they are designed to support, e.g., an elevator.

The Ontario Building code gives minimum standards for all aspects of building, including load bearing design and materials. This assures the public of a certain level of safety.

The Ontario Fire code is a law in Ontario that states that every home in Ontario must have working smoke alarms on every floor and outside all sleeping areas. Properly installed working alarms can warn people to get out of a burning building. This reduces the number of fire-related injuries and deaths.

Designing for Efficiency

Something described as “efficient” operates well without a waste of time, effort, or expense. E.g., if two students build bridges that support the same load, the bridge that uses the least amount of materials (usually by weight) is considered more efficient.

Sensors

A sensor is any device that can detect or measure real-world conditions. Different sensors can detect heat, lights, pressure, or sound, as well as changes in the amounts of these things.

Make a list of sensors found in your home:

Smoke alarm

Carbon-dioxide alarm

Thermostat

Motion sensing lights

Motion sensor alarm

Chapter 4 Test Study Guide

The following key terms and concepts should be reviewed prior to the test on:

Wednesday October 28th.

Section 4.1 Classification of Structures

1. Form and function
2. Ergonomic design
3. The 3 way to classify structures: form, function, construction
4. The 3 structural forms: frame, solid, shell (many structures are combination structures)

Section 4.2 Forces That Can Act on Structures

5. Internal forces: tension, compression, shear, torsion, (bending - combining tension and compression)
6. External forces: gravity, wind, cars, etc.
7. Describing forces: magnitude, direction, point and plane of application
8. Loads: total load, static load, dynamic load
9. Designing for forces: structures must support total load, a 100-year storm

Section 4.3 Designing for Safety

10. Risk Management:ignore the risk, avoid the risk, design for the risk
11. Designing for Loads: Engineers design for the more than the largest possible load
12. Designing for Safety: Ontario Building Code, Ontario Fire Code
13.Designing for Efficiency: What makes a structure efficient?
14. Sensors: Where are they used? How do they make people safe?

Practice Activities for Forces

Forces Lab

http://www.pbs.org/wgbh/buildingbig/lab/forces.html

Loads Lab

http://www.pbs.org/wgbh/buildingbig/lab/loads.html

4.3 Designing for Safety Quiz and Crosswords Links

Quiz 

https://sciencesource.pearsoncanada.ca/quizzes/quiz_04_3iUc4d.htm

Crossword 

https://sciencesource.pearsoncanada.ca/puzzles/puzzle_04_3/

Forces Notes #5" Internal Forces and Designing for Forces

Internal Forces

·        Can be classified as:

o   Compression – a force that squeezes or presses something together

o   Tension – a force that stretches apart to expand or lengthen

o   Shear – a force that pushes in opposite directions

o   Torsion – a force that twists

o   Bending – A force that acts to bend a component putting one side of the part in tension and the opposite side in compression

The forces occur within the human body as well since the human body is a structure; e.g., when a skater twists, torsion occurs within her body.

Designing for Forces

Engineers have to consider all these forces when designing structures, e.g., they have to consider the load of the snow on a bridge in addition to the truck.  

Engineers design structures to withstand a hundred year storm, a large storm that occurs once in a hundred years. 

Forces Notes #4: External Forces and Loads

Every structure supports a load:

§  Total load: the sum of all the static and dynamic loads

§  Static load: the effect of gravity on a structure (the weight of the structure itself) also called dead load (non-moving things on the structure add to the static load)

§  Dynamic load: the force that moves or changes while active on the structure; also called live load

o   Called “dynamic” because they change their magnitude, direction, and point and plane of application.

o   Wind is considered a dynamic load because its magnitude can change

E.g., a bridge: The static load is the weight of the bridge itself (dead load).

The dynamic load is the weight of the moving cars across the bridge (live load).

DRAW PICTURE OF TRUCK ON BRIDGE WITH LABELS HERE

4.2 Crossword for Practise

You can complete this crossword online AND in your package to practice key concepts.

https://sciencesource.pearsoncanada.ca/puzzles/puzzle_04_2/

Forces Notes #3: Describing Forces

Describing Forces

To describe forces, engineers use three main things:

• The force’s:
• Magnitude (strength)
• The size of force compared to the size and weight of object
• Direction
• Where the force is coming from
• The point and plane of its application
• Point of application: the exact location where the force meets the structure
• Plane of application: the side of the structure affected by the force 

Forces Notes #2: Internal and External Forces

Internal and External Forces

·       External force: acts on an object from outside the object; e.g., wind, gravity, earthquakes

o   Gravity

§  is a natural force of attraction

§  acts on all structures all the time

§  pulls structures towards Earth’s centre

·       other external forces

o   a person on a ladder

o   pulling a drawer open

o   sitting on a chair

o   cars on a bridge

o   wind/snow/rain

·       Internal force: one part of a structure acting on another part of a structure; e.g.,

o   tension in stretched cables on a bridge

o   compression by the weight of a roof on the walls

Section 4.2 Online Practice Quiz

Complete the following quiz to practice the concepts in section 4.2.

https://sciencesource.pearsoncanada.ca/quizzes/quiz_04_2G0jMB.htm

Chapter 4 Test Date

The date for the Chapter 4 Science test is Wednesday October 28th.

Forces Notes #1: Forces that Can Act on Structures

Forces That Can Act on Structures

• Structures constantly experience forces; they must be designed to withstand the forces they will face (Force: any push or pull)
• If the structure isn’t strong enough it may experience structural failure.
• If the structure is too strong, time and resources may have been wasted. 

4.1 Crossword for to Practice Key Terms

You can complete your crossword in the package and check your answers online by following this link!

https://sciencesource.pearsoncanada.ca/puzzles/puzzle_04_1/

4.1 Practice Quiz

You can check your understanding of classification of structures by completing this online practice quiz.

https://sciencesource.pearsoncanada.ca/quizzes/quiz_04_1RHUCb.htm

Classification of Structures Notes

Classification of structures

Structures can be classified by their:

Function – it may contain something (a glass), support something on top (a wall), or span a space (a bridge)

Construction – how they are built and what they are built from

Form – solid, frame and shell structures also there are combination structures

Solid Structures

Most are solid all the way through, but some may have small hollow parts, e.g., an apple or a mountain.

Frame Structures

Made of parts and fastened together; the parts are often called structural components. E.g., a bicycle, a tennis racket, cars, skeleton, umbrellas.

Shell Structures

Strong and hollow structures e.g., an igloo, a domed roof, a glass; these make good containers and require few materials. Even clothes are considered shell structures.

Combination Structures

Combination of frame, shell and solid structures. E.g., a house is made of solid pieces of wood that are arranged in frame. The boards arranged in a frame provided strength to the house.

Form and Function Worksheet Answers

Considering Form and Function _______

Structure	Description of Form	Description of Function
Desk	Made from wood and metal It has a rectangular flat surface with four circular legs	Used to support books, binders and to provide a surface to write on.
Chair	Four legs, sometimes attached to the desk. Made from plastic and metal. Has a back support and a surface to sit on, has four legs	Used to support our bodies in a sitting position
Coat Rack	Made from wood, metal or plastic Its shape is a tall pole with a wider base; there are hooks at the top	Used to hang coats and other clothing, to hang bags
Pen	Made from plastic. Hollow container holds the ink in a stick-like shape.	Used to write with using hands
Bulletin Board	Piece of corkboard attached to the wall with a metal frame.	Used to display work, art or information
Shelves	Made from wood The shape is a rectangular prism open on one side, there are flat wooden boards inside	Used to support books or other objects
Binder	Made from plastic, cardboard, and metal. Plastic covers the outside of rectangular cardboard.	Used to store and organize papers

Made in Bangladesh Video

The following is the complete video we viewed in class as our introduction to structures in the developing world.

Strucutres: Form and Function Notes

Structures: Form and Function

Structure: something made up of parts that are together in a particular way for a specific purpose or purposes

Form: the basic shape of the structure

Function: the job that the structure does

Force: Any push or pull that can make an object change shape, speed, or direction

Ergonomic design: designs that take into account information about the human body. Ergonomic design can help people from getting hurt doing repetitive tasks and those who are physically challenged

Science Safety Test Outline

The test outline is as follows:

1. Identify the problems and solutions in the image

2. Know what WHMIS means and the names of its symbols

3. Know what HHPS means and the names of its symbols

Know precautions for HHPS products

4. Study the names of the science equipment in the package and their uses and how to use them safely

5. Review the safety features in the lab; for example, the eye wash station, fire extinguisher, etc.

6. Review what to do when problems occur in the lab.

Good Luck!

Science Safety Activity Sample Answers

Grade 7 Lab Safety Activity                        Name ______________

The drawing you received depicts unsafe procedures in the school laboratory. Answer the following questions based on this illustration and the safety guidelines listed in your textbook on pages xviii to xx.

1.       List 6 unsafe activities shown in the laboratory drawing

a.       Fire extinguisher is blocked by the chair

b.      Girl is smelling fumes directly from the test tube

c.       There is a broken test tube and other objects on the floor

d.      There is food on the table

e.      There is spilled liquid on the floor

f.        There is a lot of mess in the lab
g.   There is an alcohol spill near open flame
h.   No one is wearing safety glasses

2.       Explain why each activity is unsafe

a.       In case of fire, you would not be able to access the fire extinguisher quickly

b.      The fumes may be harmful to her nose, or worse-she should be wafting the fumes toward her

c.       The students may be cut by the broken glass and possibly trip over other objects

d.      Food may become contaminated with poison or bacteria which would harm the student when the food is ingested

e.      Someone can slip and fall if not cleaned up immediately

f.        Equipment can be damaged and books on table can be damaged

g.   Alcohol is flammable and may cause a fire

h.   Students can damage their eyes

3.       Name 3 safety guidelines from your textbook that are not illustrated in the drawing

a.       Handle sharp objects carefully

b.      Treat all living things with respect

c.       Report safety concerns to teacher

4.       Read each statement and print T for true and F for false on the line provided

__F_____           The biology laboratory is a good setting for practical jokes

__F_____           The teacher is responsible for lab clean-up

__T_____           Spilled chemicals should be wiped up immediately

__F_____           It’s unnecessary to report minor laboratory accidents

__F_____           Performing experiments not assigned by a teacher is good creative procedure

__T_____           No chemicals or other materials should ever be tasted

__F_____           Be sure to smell materials directly from the beaker

__F_____           Only the teacher needs to know the location of the first aid kit

__F_____           Always throw broken glass into the garbage can once cleaned up

__F_____           Lab materials are inexpensive so do not be concerned if they break       

5.       What procedure would you follow in each of these situations

a)      Clothing on fire

Use the body wash station and someone inform the teacher

b)      Hot water spill on hand

Use the body wash to run cold water over burn, inform the teacher

c)       Particle in your eye

Use the eye wash station to rinse eyes for 15 minutes, inform the teacher

d)      Cut from broken glass

Inform the teacher, wash with soap and water, teacher provides a bandage

e)      Group member not following safety procedures

Inform the teacher immediately 

f)       Beaker accidentally breaks on the floor

Inform the teacher and he/she will clean up the glass, be sure no students go near glass

g)      Your group is not sure of how to do an experiment

       Ask the teacher for help

Links to WHMIS and HHPS Prezis

https://prezi.com/ko5q-owcjchz/whmis/

https://prezi.com/mmtahrfhlj1d/hhps/

***NEW DATE!*** Science Safety Test

The new date for the Science Safety Test is Tuesday October 6th.

A study guide will be posted shortly.

Science Equipment List Answers

Name	How it is used	Safety Procedures
Beaker	-mixing liquids -containing liquids -Heating substances -Measuring liquids	Use tongs or gloves if it is hot; careful not to spill; be careful because it’s fragile
Hot Plate	For heating substances	Wear safety goggles, gloves; takes a while to cool down; tie hair back, use tongs
Graduated cylinder	Measuring liquids, powders. Mix substances. Very accurate measuring.	Can be fragile. Can easily tip over, be careful. No hot substances in plastic.
Test tube	Combining substances; heating; observing.	Fragile, does not stand on its own. Use a stand.
Funnel	Pouring liquids into small containers	Pour slowly to avoid spills
Beaker Tongs	Picking up hot beakers	Pick beaker up securely in the middle. Move slowly to avoid spills.
Microscope	Viewing microscopic specimens	They are expensive and fragile; be careful.
Triple Beam Balance	Weighing objects	Be gentle with balance
Thermometer	Measuring temp.	Fragile!!! Be gentle!
Stirring rod	For stirring mixtures	Be careful it’s fragile, do not mix too quickly to avoid spills.
Erlenmeyer Flask	Sealable container, good for heating	Fragile, use tongs or gloves when hot.