Irradiated foods

After we learned about the electromagnetic spectrum, we came to class, and Mrs. M just randomly told us she had a great idea about how we each get a pair, and we would have a debate versus another pair, that meaning Mrs. M told us whether we were going to pros or cons (pros means you are supporting the topic, and cons is the opposite.) Once Mrs. M told us who was pros and who was cons, we started researching, there was no talking allowed, when we got all the research we would share it with our partner and see which are the main points and ideas. Once we were done with the researching and putting our arguments together, the debate would start. I was partnered up with Aleksej, we were the cons of irradiated food. Throughout our discussion Teodora, Monica, and Lilla (mainly Teodora) showed and told us the opposite side which in this case was the pros of irradiated food. This was a great discussion, I think and hope Aleksej and I did a good job, both teams came up with great points, and we had a lot of fun, while discussing.

Meaning of Irradiated Food:

Food irradiation is the process of exposing food to ionizing radiation to destroy microorgansims, bacteria viruses, or insects that might be present in the food. rendering foods safe to consume and extending their storage lifetime.

Pros and Cons of Irradiated food:

Pros:

• Destroys harmful substances in the food.
• Irradiation can kill or substantially reduce the number of potentially dangerous organisms in foods. Estimates range of 90 to 99%.
• No need for buying it, irradiated is labeled.

Cons:

• Destroys nutrients in food
• When life was made, it was made to die not preserve
• Not fully tested, not known if it has any long term effects.

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

Okay, so first of all, I wouldn't have to make that choice, because the only times I go to the supermarket is either to buy drinks, or chocolate, or ice cream... But that's not the point right now. If I would have to choose, I would pick the natural foods. I would not pick the irradiated one because if it’s healthy I know that it won’t harm me after washing it. Some might pick the other choice, but what i picked, i think is the right choice. Other people should pick what they think would be healthy and good for them, but whether the others' choice is irradiated, or not irradiated, they should always wash their food before eating it.

Do you think science in this case was a good invention? The population of our World-famous Earth keeps increasing and decreasing by the millisecond! However, that doesn’t influence the food storage, in any countries food has dropped of increased because of the population that has increased. I think that irradiated food can be good, and is good to be eaten, but eating it all the time I wouldn’t recommend that. Irradiated food preserves food a lot, so people can ship a lot of types of food over. Irradiated food might be good in many causes, but, to make and have the people eat more of it, scientists have to analyze and research is more to make sure nothing goes wrong in the future.

How was science used to address a global food problem with irradiation?

As said in the previous part, our population has increased and keeps increasing, in the past few years, researchers show that we, humans have been able to feed more people with irradiated food than with normal/non-irradiated food. In these past few years, we have had a lot of natural disasters; in fact, one of the biggest so far was in Japan the earthquake and tsunami that happened, washed away half of its people, and the earthquake that happened in Haiti. These natural disasters all left the country and people unstable, homeless, and hungry. With all these problems that the earthquake and/or tsunami has left, people from different countries came and started to help. As said the natural disaster has left the people hungry and they had no food, so they got irradiated food. Organizations like the Red Cross keep feeding the kids with Irradiated food and they all have a good and healthy life.

Eclipses

Why do eclipses occur?
A lunar eclipse occurs at night and a solar eclipse occurs during the day. There are only certain times when either of them can occur. A lunar eclipse can only occur when the moon is directly opposite the Sun in the sky — a full moon. Even though there is a full moon each month, obviously a lunar eclipse does not occur on a monthly basis because the Sun isn't exactly in line with the Earth and the moon. The moon's orbit is actually tilted 5 degrees more than that of the Earth; otherwise, we would see a lunar eclipse each month.

We can see lunar eclipses more readily than solar eclipses, and it has to do with proximity. The Moon is much closer to the Earth (well over 300 times closer than the Sun!), so the Earth has a much greater chance of blocking sunlight to the Moon, compared to the Moon blocking light from the Sun. Also, a lunar eclipse can be seen from a greater portion of the Earth. Solar eclipses, on the other hand, are more rare and when they do happen can only be seen by a very narrow segment of people on Earth, for a short period of time.

It is quite safe to watch a lunar eclipse with the naked eye, while watching a solar eclipse without eyewear protection can seriously damage your eyesight.



This is an example of a Solar Eclipse. ^^

This is an example of a Lunar Eclipse. ^^

What did ancient people use to think the eclipse was?
Eclipses in the ancient times were though of as my different things. In the ancient times, as some of us should, and probably do already know, ancient people didn't know what an eclipse was and couldn't find the scientific reason to it because they didn't have technology. In some ancient places, some people thought that the eclipses were evil omens, but some of them, also didn't. For example the people who built the Stonehenge looked at the eclipse as a good thing, because there is a stone made when an eclipse occurs you can see right through the stone onto it.



Which type of eclipse occurs most often? Why? Are eclipses seen from every
point on Earth?
The eclipse that is more common is the Lunar Eclipse as i have mentioned before. It can be seen by everyone on the night side of the Earth, which for me, or in my opinion, is really cool. While on the other side the solar eclipse can only be seen if you are standing on a particular spot on the Earth. I learned in class that those eclipses are very rare, and that scientists predict for one to happen in 2012. These eclipses are very rare, thus they don't happen often, they usually happen every 6-12 months.

Moon Phases

Guiding Question: What Causes the moon phases?

Directions:

· For the model place the flashlight about one meter away from Earth.

· Then place the moon between the Earth and the sun, because that’s where it is.

· After you did that observe the moon as if you are standing on Earth.

· Then sketch what you see of the moon in your notebook from four different points.

· Record your observations of the moon when moved 1/4^th of the way around the Earth in orbit, ½ of the way around the Earth and then 3/4^th of the way around the Earth in orbit.

Positions:

· Move the moon one-fourth of the way around Earth in a counter-clockwise direction.

· More the moon half of the way around Earth in a counter-clockwise direction.

· More the moon three-fourths of the way around Earth in a counter-clockwise direction.

These are the phases of the moon:

As you can see in the pictures the new moon is completely dark, because its actual position is behind the Earth and there is no sunlight there. The Waxing Crescent has a bit of sunlight, the First Quarter is half full of sunlight (not half-empty, that's just being pessimistic), the Waxing Gibbous has more sunlight than darkness, the Full Moon has complete sunlight!

The diagram above shows and symbolizes all the phases of the moon as we see them from Earth.

What did you notice about the phases of the moon?

Some things that I noticed were that the phases of the moon aren't very fast, in fact, they are pretty slow (in my head they are slow) I state this because it take the moon 29.9 days to go around the Earth

As we all might of learned or know the moon is around 4.5 million years old which is around the same age as the Earth, it doesn’t produce light on its own it reflects off of the sun. Depending on which phase the moon is located on people down here on Earth can see it in different shapes (Isn’t that cool?!) What I also learned is that we can’t see the other side of the moon unfortunately, we only see one side.

What I learned, which might be less... Or more... Or the same amount as the rest of the class has, was that the moon, very much like Earth, is 4.5 million years old, it doesn't produce or make its own light but it receives it by reflecting it off the sun. Depending on the phase of the moon, it (the moon) looks differently for us on Earth. What i also learned which i found the most interesting, was that we can not see the other side of the moon, unfortunately, or fortunately, we don't know if it is a good or bad thing, basically we can see only one side of the moon.

Why do we see different parts of the moon each night?

You see different parts, not sides, but different parts of the moon each night, just because as the moon revolves and goes around the earth, it reflects the light from the sun at different positions. If the moon didn't revolve around the Earth we would be seeing the same part of the moon each and every night, that meaning we would always see a full moon, or a new moon, etc. But the moon does move around Earth and thats why we do see different parts of the Moon although still only one side of it.

What is a lunar month?

A lunar month is the average time between successive new or full moons, equal to 29 days and a half days, specifically 29 days, 12 hours, 44 minutes

.

How does the Earth, Sun and Moon interact to cause so many things to occur?

As the planets orbit around the sun they always move, some might move/orbit faster than others and some might not. Without the sun around, we wouldn't have light, we would be living in darkness, and all the trees, plants and other living organisms wouldn't be able to function at all. Without the moon we wouldn't have tides and without the Earths tilt we wouldn't have any seasons.

What causes an eclipse and a tide?

Eclipses are caused by the Moon in its orbit passing either between the Earth and the Sun (solar eclipse) or through the Earth's shadow (lunar eclipse). The tides are caused by the gravitational attraction of the Moon (major factor) or Sun (minor factor, because it's farther away) as the Earth rotates on its axis.

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?

Hypothesis: I think that when the light of the Sun is shown on the earth, it will spread out, so that while the North Pole is not getting light, the South Pole will.

When it comes to winter in the northern hemisphere, which areas get the most concentrated light? When it is winter in the norther hemisphere, it is summer in the southern, simply concluding in the fact that that hemisphere, the southern, receives the most concentrated light. The areas close to the equator receive the most light and are the warmest, whereas the south pole will receive the least amount of light and are the coldest. While on the other side, in the northern hemisphere there is much less light. There will be some close to the equator and barely anything in the north pole.

Compare your observations between the way the light hit the equator during winter and summer between the north pole and the equator In summer, the northern hemisphere is tilted slight towards the sun, therefore there is more light in the north pole and everywhere from the equator up. In the winter, the northern hemisphere is tilted slightly away from the sun, therefor there is less light. There is hardly any light in the north pole and not very much from the equator up.

If the squares become larger from the light on the grid, what can you infer about the heat of the light shining on it? If the square becomes bigger and larger, I can easily conclude that the heat that is bearing down on it is warmer, because of the fact that the light that is shining on it, it will get warmer and the grids on it will grow bigger.

According to your observations, which areas on earth are warmest? which areas are coolest? After my conclusions and basically my personal thoughts, I would probably say that the areas nearest the equator are the warmest, because no matter what season it is, most of the concentrated light will always shine in that spot.The coldest areas on this planet are probably the north and south poles. Because even in summer, hardly any light reaches there to warm it up.

What time of year would the toothpicks shadow be longest? When would it be shortest? I would guess that the time of year when the shadow is longest would be summer because that's when the most light would be shining on it, and because light can't break through barriers, it causes a shadow. Which means that the time of year when the shadow would be shortest would be winter because only a little light is shining on it.

How are the amounts of heat and light received in a square related to the angle of the suns rays? The more concentrated the sun makes its light, the brighter and straighter the squares will appear to be on Earth. The angle of the light will be causing the squares to appear stretched or faint when it comes at it from a slight tilt.

Use information form your observations to write an explanation of why the seasons change
Because of the Earth's orbit, the southern and northern hemisphere will change and alternately tilt to or from the sun. The light and heat that is reflected from the sun is what that, just basically causes the seasons. During the period that the Norther Hemisphere is titled to the sun, it's going to be either the Summer season, or the Spring season, whereas when it's tilted away it's either going to be the Fall season or the Winter season.

Noise Pollution Report

Roy Elal

7B

Noise Pollution Questions

Mrs. Medenica

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 light pollution), 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.

Who or what does it affect? Noise pollution affects everyone, yet this problem is largely ignored by most people. Upon hearing loud noises and sounds, we might be irritated but feel at a loss to do anything about it. Noise pollution comes from various sources including traffic, airports, industries, factories and highly populated urban areas. However, these are not the only ways we can be affected by noise pollution. A loud musical event such as a rock concert, occupational noises, and large crowds are just as detrimental to humans, especially with repeated exposure. For example, the other day I watched a movie at the cinema in Usce with a couple friends, and the noise coming from the movie was loud when there was a war scene, or something similar, the chairs were shaking because they made the noise be so loud. Also once we came out of the movie we could barely hear ourselves talking. (Bad noise quality for Usce cinema!!)

What is the problem or issue with noise pollution? The main problem with noise pollution is hearing loss, or complete deafness. If noise pollution was never a problem, and it was able to be completely ignored, then it would not take a big part of our lives. Noise pollution is described as irritating, or unbearable to humans and occasionally to animals too (meaning not all animals are disturbed with the same sound.)

How are science and technology being used to help reduce noise pollution? As we understand already, Noise Pollution is already a great problem, and what some companies such as Apple and Panasonic, are trying to do, is soundproof your walls, windows, TVs, and speakers so you can play your loud music at parties without interrupting or disturbing whatever your neighbors are doing. Earphones usually do the trick if you are trying to listen to your music alone.

What limitations are coming up in the designs of Noise pollution proof designs? Although as we all know that noise preventing materials/technology is and would be selling huge on the market, there will be some defects. Even though you can have all the noise preventing materials for your doors, windows, or anything, your neighbors will still be able to hear your music, and noise proof earphones or headphones will do the same if you turn the volume up to high. So, although you can have the most soundproof home in the world, there is still a possibility that others will hear it from outside your home.

What is being done to stop Noise Pollution? As I already mentioned above, Apple and Panasonic whom have made materials to soundproof your home are trying to stop Noise Pollution by doing that. Except that I can only compare to the early 1900s where they had no soundproof materials, and their cars made a lot of noise, and so did most of their technology.

Use of waves reflections

How does the use and study of waves affect societal well-being? The use and study of waves, definitely affect our society of 'well-beings', because every time we, we as in scientists who study waves, find out something, or create something that can prevent us from being damaged either mentally, or physically because of a violent type of wave, the word spreads over the internet, the television news, the newspapers, the people who read the newspapers, watched the news, or read on the internet about that new thing that can prevent damage and tells someone about it. That is how everyone can find out about this new product, or new discovery of a product which is going to be made in the future to help and avoid from violent waves. We studied Electromagnetic Spectrum first, where we learned that scientists have discovered many new ways to explore space, human anatomy, cures, etc. We studied Radio Waves, whom have helped us in many ways, mainly with radio and TV, thus if we, again we as in scientists who have studied this topic, wouldn't have found out and researched about Radio Waves information wouldn't have been able to be passed on as easily and people wouldn't have found out about important events as easily. Microwaves came next. Microwaves help by making things around the house simpler than they would be. Infrared waves came after that, and what we learned about Infrared Waves was that they provide a source of heating, and are also used for specific military uses. Visible lights are the lights that we can see, whereas without visible lights, we wouldn't be able to survive. Ultraviolet Waves were next for us in the Electromagnetic Spectrum studies. Ultraviolet Waves are probably considered one of the most important in the Electromagnetic Spectrum. Ultraviolet Waves are the waves who come from the sun, these rays allow plants and animals to develop themselves, and basically thrive. The most powerful wave in the Electromagnetic Spectrum is the next. The Gamma Ray Wave. By learning about Gamma Rays, we have obviously learnt a lot about space. By mobilizing Gamma Rays we have been able to go and see the deepest and most difficult places in space such as black holes and supernovas.

The next Waves topic/unit we began was seismic and water waves. By studying this, scientists who study this topic, have been able to learn when a Tsunami or Earthquake is approaching, and where it is approaching, why it is approaching that place (as in what happened with the tectonic plates, or volcanoes that caused it), and how they can inform the people living in that area as soon as possible so that many lives can be saved. We learnt about fault lines and how the work, and what the changes that are made in them mean and how they can make a difference in our lives. Scientists now know how to inform people about when an Earthquake or a tsunami is approaching their area, and will give them enough time to run away and leave that are that the Scientists are thinking the Tsunami or Earthquake will hit. Also we studied many different ways to measure Tsunamis and Earthquakes, such as with the rector scale. By learning about how these types of waves travel, and their effects, we, and again I don't mean we as in the 7th grade but as in Scientists, can assure a safer Earth community for all the citizens around the world.

Sound Waves were the last topic we studied. Sound is the reason for some of life's most interesting, important and amusing components! With sounds we can create things such as music, laughter, conversation, alarms from danger, and many more. Although, the negative of Sound Waves is Noise Pollution, which can create hearing loss, or deafness, causing one not to be able to experience all of the good components of Sound Waves. Noise pollution is just unpleasant sound, which can get as violent as causing hearing loss or complete deafness! Right now there is research about how to improve already existing soundproof materials for your doors, windows, speakers, TVs, and basically your house, also there are earphones and headphones that are soundproof.

What did you like? What I enjoyed in this Waves Unit, is probably the typical student answer... The Experiments and labs! I am not just saying that as a "We did only 2 labs and the rest of the time we took notes" because it really wasn't like that. We did a lot of projects, a lot of labs, and a lot of group work, which in most cases makes me specifically much more productive than working individually. Another thing I really enjoyed were all the videos we got to watch! Basically I think this was one of the most creative, and involving units we had this year, although we did have *a lot* of other fun and involving units.

What would you change or add for next year's grade 7 students?

I personally think that this unit was a bit long. For next years' 7th graders I think the unit should be a bit shorter, or more separated into different units, therefore having more big projects which they can present infront of us (next year's 8th graders) next year!! :D

What did you learn during the unit? (Looking at the picture you drew-how has your knowledge changed?)

I learned so much this unit that was completely unknown to me before. I learned things like that sound, light and earthquakes are even connected to waves, whereas before I thought waves were only the ones in the sea. Not only did I learn about that sound, light and earthquakes are connected to waves, but I learned about what components affect the way they reach or affect us, and how they travel! At the beginning of the unit, which now seems so far back, we learnt that there were three basic types of waves; longitudinal waves, transverse waves, and combination waves. We learnt that many waves must travel through a medium such as air or water, and that the names of these waves were mechanical waves. Later on during our Wave unit we learnt about water waves, sound waves, and light waves, and what type of wave they are. We also did essays about how those waves can affect us, and the people in our community, and basically all the citizens of Earth, and how science is being applied in the study of these waves.

How does the density of a material affect the properties of sound traveling from a tuning fork?

Guiding Question:

How does the density of a material affect the properties of sound traveling from a tuning fork?

Hypothesis: The more dense the surface the lower the pitch

Controlled Variable

Tuning fork- G 384

Force- one medium hit

Manipulated Variable

Object- we are using four different types of materials.

Materials

• Tuner
• Notebook
• Glass
• Wood
• Aluminum
• Locker material

Tuner – G-348

Surface	Pitch Loudness
Aluminum 2800 kg/m3	Aluminum is the densest material that we tested. What we observed is that Aluminum produced the softest sound.
Glass 2500 kg/m3	Glass was a lot louder that aluminum was, it had an annoying sound. While Blaise was listening to it, I could hear it clearly about 1/2 meter away from the glass.
Wood (oak) 600 kg/m3	Wood was a lot louder, than both aluminium and the Glass, although it had a softer sound than the Locker.
Locker (steel) 222.260	The locker was the loudest, and least dense from all the materials above. While Blaise was listening to the locker, i stood about 2 meters away from the locker and could hear it.

Conclusion

What I conclude from this lab/experiment, is that the less dense the material, the louder the sound is. It turns out the hypothesis I had was incorrect in the end. What I have learned from this lab, is that the less dense a material is, the louder the sound will be once heard with a tuning fork's vibration.

If I were to do this experiment again, I would probably have used more materials, such as a phone, laptop, or a toilet seat. I would find that pretty interesting, although only if i wouldn't have to put my head on the toilet seat (disgusting.)

Guiding Question:

How does the density of a material affect the properties of sound traveling from a tuning fork?

Hypothesis: The more dense the surface the lower the pitch

Controlled Variable

Tuning fork- B 480

Force- one medium hit

Manipulated Variable

Object- we are using four different types of materials.

Tuner – B-480

Surface	Pitch Loudness
Aluminum 2800 kg/m3	Aluminum is the densest material that we tested. What we observed is that Aluminum produced the softest sound.
Glass 2500 kg/m3	Glass was a lot louder that aluminum was, again. While it also had a very intense sound.
Wood (oak) 600 kg/m3	Wood was a lot louder, than both aluminium and the Glass, and had an intense ringing.
Locker (steel) 222.260	Surprisingly this material was way louder than any of the other materials, even with a shorter tuner it was a very loud and intense pitch and sound.

Conclusion:

Next to the first lab Blaise and I completed, this was the probably the same. In this lab we used a different tuner; we used one high, and one shorter tuner. Blaise and I wanted to check if the results of the two different tuners would be identical, or completely different, or in the middle. What we found out is that the two tuners made almost identical sounds. What we found out is that with both tuners, the less dense the material was, the louder the sound was.

Further Inquiry:

If I were to redo either, or both of these tests, I would, as mentioned in the first conclusion, that I would attempt to use a locker, a phone, and/or a toilet seat. I would use these materials because I think they would make a different sound. Al-in-all, I think I worked pretty well on this project, and that me and my partner (Blaise) did a pretty good job together!

Notes on Bill Nye Sounds Video

• Sound is tiny vibrations in the air
• Oscilloscope- makes sound waves visible
• The ear is like a funnel that helps sound go into the eardrums
• Sound travels faster through metal and brick faster than through air
• Sound travels 18 times faster through metal than air
• An echo happens when sound bounces off something
• When sound enters the ear canal it becomes smaller
• Higher frequency = Higher pitch
• Lower frequency = 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 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 1 cm away from the middle. Let it go. How far does the band move? Describe the sound you hear in a table.

3. Repeat step 2 four more times. Each time, pull the band back further. Describe how the sound changes each time in the chart below.

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 thicker 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 changes.

6. Pull the rubber band even tighter and repeat steps 1-2. Observe how the sound changes. Record your observations 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 partners move his or her hand so that the rubber band is a little bit shorter. Repeat step 2 and observe the change in the sound.

9. Repeat step 8 two more times, making the rubber band a little shorter each time. Record your observations of the change in sound.

Experiment #1

Experiment #2

CONCLUSION:

1. How did the sound change when you changed the amplitude (how far the rubber band was away from the middle point)?

The farther away you pulled it, the louder and sharper the sound became.

2. What happened when you changed the thickness, length, and tightness of the rubber band?

Thickness: the thicker the band is, the duller the sound

Tightness: the tighter the band is, the higher the pitch

Length: the shorter the band is, the higher the pitch

3. 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 can tighten the string, which will make the pitch higher.

Wave and Ball Barrier Interaction Lab

Guiding Question:

What happens to a wave as it hits a surface it cannot pass through?
Once a wave hits an object it can't go through, i just bounces back, making a pattern between the waves where they just cross over each other. I made several tests where i saw that the wave made an interesting pattern when it bounced back from the barrier. Once the wave hits the barrier and starts bouncing back, some of the energy of the wave starts decreasing, because of the pressure against the barrier. When a wave meets a barrier and it reflects off the surface of the barrier, some, or most of the waves energy is lost, because of the pressure that is being made against the surface of the barrier. When a wave finds a hole in a barrier, and manages to pass through, it either bends or spreads out, This is called diffraction. Another thing I saw, was that the interference between two waves or more happens, they affect each other.

Does energy (density of the ball) affect the wave’s path?

In my mini lab I noticed that the density of the ball does affect the wave’s path. I used three different types of balls: a medium sized bouncy ball, a light Styrofoam ball, and a small orange light plastic ball. In the experiment the Styrofoam ball and the small orange plastic ball were both every light, the rubber bouncy ball was the heaviest. When I tested the bouncy ball I found that it made the widest triangle when bouncing off the wall.The bouncy ball had the biggest angle of incidence, and angle of reflection.The foam ball made the second biggest triangle when reflecting off of the wall. It had the second biggest angle of incidence and angle of reflection. The small light orange plastic ball made the smallest triangle when we were testing. The small light orange ball had the smallest angle of incidence and angle of reflection. I suppose that this was the lightest or the least dense ball that I had. I noticed that when the ball hit the wall refraction occurred, when it hit the wall the balls slowed down.

How is the angle at which the ball (wave) hit the wall related to the angle at which it bounces back?
As I found in my testing my lab I found that the angle at which the ball hits the wall it comes back at about the same angle. When testing the lab 10 times each one of my results ended up to be the lightest and least dense the ball the smaller the triangle the ball would make after the ball reflected the barrier or the wall. I did a little experimenting with the angles I rolled the wall and found that it would reflect off the wall about the same place every time. I noticed that the incoming "wave" reflected off the wall at the same angle. This is because the law of reflection states that the angle of reflection equals the angle of incidence. To conclude this lab, I would like to say that it was a very interesting and inventive was to learn how waves reflect of a barrier.