Reasons for the Seasons

Reasons for the Seasons

Guiding Question: How does the tilt of Earth’s axis affect the light received by Earth as it revolves around the sun?

Skills Focus: making a model, observing, inferring, predicting

Materials:

• books
• flashlight
• paper
• pencil
• protractor
• toothpick
• acetate sheet with thick grid lines drawn on it
• plastic foam ball marked with poles and equator

Producer:

1. Make a pile of books about 15 cm high.
2. Tape the acetate sheet to the head of the flashlight. Place the flashlight on the pile of books.
3. Carefully push a pencil into the South Pole of the plastic foam ball, which represents Earth.
4. Use the protractor to measure a 23.5° tilt of the axis of your Earth away from your ‘flashlight sun.’ This position represents winter in the Northern Hemisphere.
5. Hold the pencil so that Earth is steady at this 23.5° angle and about 15 cm from the flashlight on. Dim the room light.
6. The squares on the acetate should show up on your model Earth. Move the ball closer if necessary or dim the room lights more. Observe and record the shape of the squares at the equator and at the poles.
7. Carefully stick the toothpick straight into your model Earth about halfway between the equator and the North Pole. Observe and record the length of the shadow.
8. Without changing the tilt, turn the pencil to rotate the model Earth once on its axis. Observe and record how the shadow of the toothpick changes.
9. Tilt your Earth 23.5° toward the flashlight. This is summer in the Northern Hemisphere. Observe and record the shape of the square at the equator and at the poles. Observe how the toothpick’s shadow changes.
10. Rotate the model Earth and note the shadow pattern.

Analyze and Conclude

1. Observing: When it is winter in the Northern Hemisphere, which areas on Earth get the most concentrated light? Which areas get the most concentrated light when it is summer in the North Hemisphere?  The
2. Observing: Compare your observations of how the light hits the area halfway between the equator and the North Pole during winter (Step 6) and during summer (Step 9). 
3. Inferring: If the squares projected on the ball from the acetate become larger, what can you infer about the amount of heat distributed in each square?
4. Inferring: According to your observations, which areas on Earth are consistently coolest? Which areas are consistently warmest? Why?
5. Predicting: What time of year will the toothpick’s shadow be longest? When will the shadow be shortest?
6. Drawing Conclusions: How are the amounts of heat and light received in a square related to the angle of the sun’s rays?
7. Communicating: Use your observations of an Earth-sun model to write an explanation of what causes the seasons.

Waves Unit Reflection

How does the use and study of waves affect societal well-being?
During this Unit we learned about Seismic Waves, Water Waves, Electromagnetic Waves, and Sound Waves. In the beginning of the unit I didn't really know anything about wave only about Microwaves but not as much as I know now. Also, I know about the waves that are in pools or at the beach. Without waves how would we be able to help humans from death and diseases without UV rays (new born babies in hospitals), x-rays or gamma rays (used in hospitals to treat cancer). Doctors use magnetic resonance and radio waves to see a picture of human’s tissue. Radio waves and the Doppler effect are used to find the speeds of moving vehicles and of moving balls at sport events such as tennis matches. 


What did I like?
I really liked how we started the whole unit. How we listened to songs, while that drawing waves, what we thought waves were. It was very good way to see how we would be embarrassed, because of our small knowledge about waves. 
What would you change or add for next year's grade 7 students? 
I think it would be more fun if there would be more group work

Food Irradiation

Step 1: During class we talked about food irradiation. We were assigned in partners to research about the cons and pros of food irradiation. Monica, Teodora and I were researching about the pros, Roy and Aleksaj were researching about the cons of food irradiation. 


Step 2: Irradiation is the process of treating food and other consumer products with gamma rays, x-rays, or high voltage electrons to kill potential harmful bacteria and parasites, delay sprouting, and increase shelf life. Irradiation is also referred to ass "ionizing radiation" because it produces energy waves strong enough to dislodge electrons from atoms and molecules, thereby converting them to electrically charged particles called ions.  Ionizing radiation reduces the number of disease causing organisms in foods by disrupting their molecular structure and killing them.  Other terms commonly used to identify ionizing irradiation are "cold pasteurization" and "irradiation pasteurization".
Food irradiation makes food safer to eat, and also could stay fresh for longer, but it can kill many healthy vitamins, like vitamins A, B-1, E and C, that are useful in the daily life, but also cooking the food can kill those vitamins. As well the once that are harmful to human. 


Step 3: 

Pros: 

• Irradiation can kill or substantially reduce the number of potentially dangerous organisms in foods.  Estimates range for 90 to 99.9%.
• Irradiation can kill insects and pests infesting foods such as grains and flours without leaving chemical residues.
• Irradiation can be used to sterilize food for immune-compromised individuals such as AIDS 

Cons:

• Irradiation at recommended doses will not eradicate all pathogens. The remaining organisms are by definition "radiation resistant" and may create super strains of hard-to-kill pathogens.
• Irradiation at current allowable levels is ineffective against viruses such as the Norwalk virus found in seafood.
• Irradiation can only be used on a limited number of foods.  Fresh produce such as lettuce, grapes, tomatoes, and cucumbers turn mushy and unpalatable.  Thus, the risk from contaminated fresh produce, a major carrier of food borne disease, cannot be fully addressed by irradiation.

Step 4: You see two containers of a food at the supermarket.  One is irradiated; one is not.  The price is the same.  Which would you buy?  Explain why. 

I think if I always had the choice to pick between natural and not natural food, I would always pick natural. I would chose that food because its the same price but natural food is healthier since it has the vitamins, but irradiated food kills most of those vitamins that would be healthy for human.

Noise Pollution

What is Noise Pollution?  Noise pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. As with other forms of energy pollution (such as heat and lightpollution), noise pollution contaminants are not physical particles, but rather waves that interfere with naturally-occurring waves of a similar type in the same environment. Thus, the definition of noise pollution is open to debate, and there is no clear border as to which sounds may constitute noise pollution. In the most narrow sense, sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis. In the broadest sense of the term, a sound may be considered noise pollution if it disturbs any natural process or causes human harm, even if the sound does not occur on a regular basis.


How does it effect to your ear? Your ears were designed to process naturally-occurring sounds, and they are beautifully adapted to handle that task. They are able to detect sounds of intensities that vary across many orders of magnitude, and to meaningfully transmit those signals to our brains. But they are not well equipped to deal with the high noise levels that are common today, because such loud sounds occur only rarely in nature. The ear is a complex structure, processing sound through several stages in the outer, middle, and inner ear. Although the eardrum may sometimes be ruptured by severe noise (acoustic trauma) or pressure changes, the part that is most vulnerable to damage by noise lies more deeply, in the inner ear, where the final processing takes place before the sound is converted into nerve impulses that are transmitted to the brain. The prominent structure in the inner ear is the spiral-shaped cochlea, which is a fluid-filled tube lined with delicate, microscopic hair cells that pick up the vibrations caused by sound waves. When they are overworked by too much exposure to loud sounds, the hair cells become metabolically exhausted and can temporarily lose their function. Fortunately, they are able to recover from the auditory fatigue caused by too much noise, but if overexposure is too long or too frequent, they can't cope, and they die. There is no pain or bleeding when this occurs. 


Ways you can protect yourself from noise pollution:

• Know which noises can cause damage (those at or above 85 decibels)
• Turn your music down, especially when using headphones
• Wear earplugs or proper earmuffs when involved in a loud activity (special earplugs and earmuffs are available at hardware and sporting goods stores)
• Be alert to loud noise in your environment
• Protect the ears of children who are too young to protect their own
• Make your family and friends aware of the dangers of noise pollution
• If you think you have hearing loss, see your doctor or nurse. You should have a medical exam by an otolaryngologist  (a doctor who works on the ears, nose, throat, head, and neck) and a hearing test by an audiologist (someone who tests and helps people with hearing loss)  

How can science reduce noise pollution?

Trees, not only absorb carbon dioxide, provide shade, prevent erosion, but they can also help muffle noise. Think of trees as big, leafy, air-purifying, oxygen-producing, white noise machines. Acting as shields, trees reduce the intensity of the sound waves considerably and it is the sound produced by the wind passing through the leaves that really helps muffle noise. A properly-designed buffer of trees and shrubs can reduce noise by about five to ten decibels-or about 50 percent as perceived by the human ear, according to the USDA National Agroforestry Center. For maximum effect, experts suggest planting a variety of both hedges or shrubs and taller trees to create a wall of foliage from the ground up. Such examples as cottonwoods, poplar and aspen trees are especially good at noise reduction because their leaf-shapes produce a good, strong rustling sound

Tunning Fork Lab

Guiding Question:  How does the density of a material affect the properties of sound traveling from a tuning fork?
Hypothesis:  If the dense of the surface is high then the pitch will be lower. 
Material: 

• Tuning fork
• Two types of surface:
• wood
• glass

Procedure:
1. Take a pencil and a notebook before you get started with your experiment, because you wouldn’t want to miss something out, otherwise everything would be incorrect.
2. Take a tuning fork of normal size and hit it on each material. You should feel the vibration of the tuning fork while you’re holding it.
3. Get a timer/watch stop and time how long the tuning fork vibrates. Save your observations on a document or in your notebook.
4. Repeat the steps above.

Material	Observation
Wood	Long vibration, lasts for long time
glass	Annoying sound, loud and intense

Conclusion: My hypothesis was right if the material has higher dense then it will have a lower pitch.

Properties of Sound Lab

Purpose: To determine how changing amplitude and frequency can change how a sound is perceived.

Procedure: 

Experiment 1: Amplitude

1. Have two partners each hold one end of the thicker rubber band and pill until the ribber band is taut (not loose).
2. Pill the rubber band about 1 cm away from middle. Let it go. How far does the band move?1-2 cm Describe the sound you hear in the table below.
3. Repeat step 2 four more times. Each time pull the band back further. Describe how the sound changes each time on the chart below. 

Results:

Experiment 1

Experiment 2: Frequency

1. Have 2 partners each hold one end of the thicker rubber band and pull until the rubber band is taut (not loose).
2. Pull the rubber band about 2 cm away from the middle. Let it go. Observe the sound.
3. Repeat steps 1-2 with the thin rubber band and describe the difference in the chart below.
4. Now, take the ticker rubber band again. Repeat steps 1-2.
5. Now pull the thicker rubber band a little bit tighter and repeat steps 1-2. Observe how the sound change.
6. Pull the rubber band even tighter and repeat steps 1-2. Observe how the sound changes. Record your observation in the chart. 
7. Last experiment: have two partners hold the thick rubber band just like in step 1. Repeat step 2 and observe the sound.
8. Now, have one of your partner move his or her hand so that the rubber band is a little bit shorter. Repeat step 2 and observe the change in sound 
9. Repeat step 8 two more times, making the rubber band a little shorter each time. Record your observation of the change in sound. 

Results:

Experiment 2:

Conclusion:

How did the sound change when you changed the amplitude (how far the rubber band was away from the middle point)? It always became higher all the time.

What happened when you changed the thickness, length, and tightness of the rubber band? Thickness: the thicker one was deeper.

Length: the longest was high

Tightness: The loose one was deep

Sally is playing the guitar and notices that one of her strings is flat (pitch is too low). What can she do to fix this? She has to make the string tighter 

Earthquake Safety

Have you ever wondered what you should/have to do in an earthquake? Well, here will be some basic things that you should do.

The first step of the safety plan is to be prepared for the earthquake, even if it hits all the sudden. The best thing to do in an earthquake is the 'Drop, cover, and hold' method. What you have to do is drop to the ground and cover yourself, with your hand. Then you have to hold onto something. 

The second thing you should do before is to make safety kits! This is really important because at the time when the disaster already hit there won't be time to get all the supplies you need. What you need in this safety kit? The most important things that you need are: 

• Water: 1 gallon per person per day (a week's supply of water is preferable)
• Water purification kit
• First aid kit, freshly stocked
• First aid book
• Food
• Can opener (non-electric)
• Blankets or sleeping bags
• Portable radio, flashlight and spare batteries
• Essential medication
• Extra pair of eyeglasses
• Extra pair of house and car keys
• Fire extinguisher : A-B-C type
• Cash
• (Only if you have pet(s))Food, water and restraint (leash or carrier) for pets
• Cash and change
• (Only if you have a baby sister/brother!)Baby supplies: formula, bottle, pacifier, soap and baby powder, clothing, blankets, baby wipes, disposable diapers, canned food and juices.

This list should last at least 72 hours! 

Before an earthquake:

• Learn how to survive during the ground motion.
• Teach all members of your family about earthquake safety. This includes: 1) the actions you should take when an earthquake occurs, 2) the safe places in a room such as under a strong desk, along interior walls, and 3) places to avoid such as near windows, large mirrors, hanging objects, heavy furniture and fireplaces.
• Arrange your home for safety
• Anchor heavy appliances and furniture such as water heaters, refrigerators and bookcases.
• Store flamable liquids away from potential ignition sources such as water heaters, stoves and furnaces.
• Learn where the main turn-offs are for your water, gas and electricity. Know how to turn them off and the location of any needed tools.

During an earthquake:

• If you are indoors, stay there. Quickly move to a safe location in the room such as under a strong desk, a strong table, or along an interior wall. The goal is to protect yourself from falling objects and be located near the structural strong points of the room. Avoid taking cover near windows, large mirrors, hanging objects, heavy furniture, heavy appliances or fireplaces.
• If you are cooking, turn off the stove and take cover.
• If you are outdoors, move to an open area where falling objects are unlikely to strike you. Move away from buildings, powerlines and trees.
• If you are driving, slow down smoothly and stop on the side of the road. Avoid stopping on or under bridge and overpasses, or under power lines, trees and large signs. Stay in your car. 

After the earthquake:

• Check for injuries, attend to injuries if needed, help ensure the safety of people around you.
• Check for damage. If your building is badly damaged you should leave it until it has been inspected by a safety professional. 
• If you smell or hear a gas leak, get everyone outside and open windows and doors. If you can do it safely, turn off the gas at the meter. Report the leak to the gas company and fire department. Do not use any electrical appliances because a tiny spark could ignite the gas.
• If the power is out, unplug major appliances to prevent possible damage when the power is turned back on. If you see sparks, frayed wires, or smell hot insulation turn off electricity at the main fuse box or breaker. If you will have to step in water to turn off the electricity you should call a professional to turn it off for you.

My family earthquake plan

My parents:

My parents can't go under their bed if a earthquake occurs in the middle of the night. So, they have to rush to the bathroom next to their room. They should go there because there aren't any windows, and the boiler is in another bathroom, so, that's the safest place for my parents.

My brothers Akos and Vilmos:

The best thing that my brothers could do is to go under he's own desk and be there when the earthquake happened. Also, they could go under their bed.

Me: 

I have a bunk bed. So, if an earthquake occurs in the middle of the night i would be at the safest place in my room, but there are possibilities that the upper part of the bed falls on me, luckily my dad fixed the bed so this won't happen. If I didn't had a bunk bed then the best place would be under my desk because that is the safest place then.