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BrandyBoy72

Commonly pondered question:

How much does all the air on the Earth weigh?

Make your predictions now: a) more than the Earth itself  B) 0 kg, air weighs nothing, duh c) More than all the birds on Earth  d) 7.89 kg

 

One cubic meter (1000 liters) of air weighs 1.292 kg (so if you chose d you are probably already wrong)

But that doesn't help us much, because as you go further up in the atmosphere, the density changes. The mass of the air is the same, but there is just less of it per cubic meter.

Calculations:

Another way to approach this problem: the air pressure at sea level is 14.7 psi, in other words, all the air in a 1in x 1in area all the way up to the top of the atmosphere would weigh 14.7 lbs

***we'll convert to more physics like units later***

Now we need to find out the surface area of the Earth: 

Earth's radius: 2.5E8 in (again we'll convert later)

Surface area of a sphere: A = 4*pi*r2 = 7.854E17 in2 

Now multiply: 7.854E17 in2 x 14.7 lbs/in2 = 1.155E19 lbs

All the air in the Earth's atmosphere weighs approximately: 5.3E14 kg

Compared to:

All the birds on the Earth: net weight(very approximately) = 3.6E12 kg (if you chose c at the beginning, you win *suggest prizes in the comments*)

The Empire State Building(approximately) = 3.3E8 kg

500 really big boulders(exactly) = 3.4E4 kg

Image result for duck

BrandyBoy72

In my previous post, I realize that I gave an incorrect answer to the solved problem. Not so much as incorrect, the number sure is right, but it is a vector (has magnitude and direction) and I treated it like a scalar (magnitude only), by leaving out direction. The answer should have been a=2.254 m/s2 downwards. Another thing I left out in the original answer was units, something that it is common for me to neglect or often mess up. Any time I am read a word problem for the first time I do what I was taught, take out only the useful information, ie. the numbers. And not uncommonly these numbers are connected to units, which I will inconveniently ignore. And by the time I get to the end of the problem, I will probably have an answer that is off by some power because I have not converted grams to kilograms or something like that. So remember: always use correct units and label directions on vectors!

BrandyBoy72

A friend of mine in AP physics 1 needed help on a web assign question in which a man's weight changed by .77 times after the elevator he was on started to accelerate. I explained to him how I would set up a system of equations where mg=weight(w) and the weight afterwards .77w=m(g+aelevator). And then set them equal: .77mg=m(g+a). m's cancel and then you solve for a getting a=2.254. A throw back to the test with that one SRQ with the guy pulling on the elevator, shows us that elevator problems plague physics students everywhere. But it also shows us that we are learning and we have at least made some progress in our physics careers.

BrandyBoy72

Archery is pretty intense when you think about it with physics on the mind. There's tension in the string, aerodynamics (arrow dynamics), kinematics, oscillation, and probably a whole lot more things too. In archery there is this thing known as the "Archer's Paradox" which has to do with the oscillation of the arrow during it's flight. Image result for archer's paradox physics

As an arrow flies through the air, because of the flexibility of the arrow shaft, there is an oscillation that occurs. If the arrow were not flexible, if it were rigid, then it would not fly in the direction it is aimed. You can imagine that the arrow is bending around the bow as it is shot. This oscillation changes based on the flexibility of the arrow and the strength of the bow.

BrandyBoy72

Can you travel at infinity miles per hour? Well, infinity isn't really a number so, probably not. But how fast could, we'll say a person, travel? I would say the speed of light is the fastest possibility, but let's start out a bit more realistic. Usain Bolt can run at 28 mph, but this is physics, so 12.5 m/s. Not a bad start. How about something faster, the fastest train is the Maglev, at 120 m/s. The fastest land vehicle - Thrust SSC at 341 m/s. The fastest speed by a manned vehicle was the Apollo 10 at 11082 m/s, but that's still only about 0.0037% the speed of light. But wait, we're on the Earth, aren't we, and that's moving fast, about 30000 m/s. And now that we've considered that, how fast is the milky way galaxy moving? 581152 m/s! That's 0.19% the speed of light. I don't think that it is reasonable that people will get close to traveling faster than our galaxy, at least any time soon, so guess it's time to give up. 

But, let's consider something, could we already be traveling at the speed of light? Here's the idea: there is a person at point A standing still, and a car moving at 16 m/s, and there is a point in the car, point B, where relative to that point, the car is not moving (kind of like how relative to us, the Earth is not moving, but relative to the Sun, it is moving quite fast). So, from that point B in the car (if you can imagine) the person standing at point A is moving, relative to you being still, at 16 m/s.

So, considering this example of relativity, can we say that relative to a photon, we are moving at the speed of light? Yes. Wait! No, no, no that can't be, we did not consider something, I said there was a relative point B where the car was not moving, so there would have to be a point where, relatively, a photon is standing still, and that is not possible in any reference frame. (Also technically there is no reference frame where anything but a photon can be moving at the speed of light) - but we still went through with this thought procedure in light of that... get it?

BrandyBoy72

P=MV

Momentum of the Earth (Linear):

Mass of the Earth: 5.972*10^24 kg  ;  the weight of the Earth is measured using the equation FG=(Gm1m2)/r2 taking an object that has mass and finding the force that the Earth exerts on it.

Velocity of the Earth: 30000 m/s  ;  We find the velocity of the Earth by knowing that the Earth travels around the Sun in one year, now we only have to find how far it travels. We have to find the length of its ellipse around the sun, which is approximately a circle (or close enough - this is physics after all where 9.8=10...) So we have to find the radius which is the average distance from the Sun to the Earth which is known as an Astronomical Unit (AU) which is 149,600,000 km. So C=2*pi*r2 ; C=2*pi*(149,600,000,000m)2  and divide that by one year to get the velocity.

Now multiply mass and velocity together to get momentum:   5.972*10^24kg * 30000m = 1.7916*10^29 N*S - pretty big

BrandyBoy72

Recently I went to an indoor climbing facility downtown, called Rock Ventures. I love rock climbing, there's a thrill in all that built up gravitational potential energy. However, it is completely safe thanks to our friend the pulley. There are multiple types of rock climbing, indoor climbing, free climbing, and solo climbing. Solo climbing has no ropes involved whatsoever, just a person on a cliff. Free climbers use ropes, but only to prevent from injury in segments, not to assist in the climb. Indoor or sport climbing is what I was doing, this type involves a pulley system. The interesting part of this system, not really having to do with pulleys, is the ATC that is used when belaying (yes it stands for Air Traffic Controller, you'll soon see why)

The ATC is used by the belayer, a person on the ground spotting the climber, to control their ascent and descent and how much slack is in the rope. The ATC is a device which the rope goes through to be manipulated by the belayer. There is a lead rope and a slack rope, when they are parallel, the rope is free to slide - in this position the belayer can pull excess rope through as the climber ascends, getting rid of slack makes the climb safer in case the climber would fall. When the slack part of the rope is pulled down towards the ground, there is a frictional force between the ATC and the rope, which under even a large amount of tension, would not allow the rope to slide.

The ATC is a very simple, yet genius device that makes it possible to safely climb for fun, and for that, I thank physics

belaying.jpg

BrandyBoy72

On Saturday it was very wavy out on lake, like 6 ft waves out there. It was pretty scary being out there thinking that your boat could be capsized by some monster waves. And I was thinking, why was it so wavy? It must have had something to do with the sudden change of the weather, right? Well, waves, as we know, are not the traveling of matter, but energy through a medium. So, the water is not being transferred, but energy is being transferred though the water. This energy actually, like most things on the Earth, comes from the sun. This sounds pretty weird, at least it did to me, but waves start from wind and wind is created by the uneven heating of the Earth by the sun, so waves are just... solar energy? Yeah that makes sense. The amount of energy put into a wave is determined the same way the amount of energy put into any object would be determined. The speed of the force on the water, and the duration of that force. The faster the wind is moving and the longer it is acting on the water, the bigger the wave will be. This makes sense because it was also very windy on Saturday. So, the air was moving from an area of low energy (the cold air over the lake), to an area of higher energy, probably because of that heat wave that just left us. And that energy from the wind was transferred into the water, creating the giant waves, pretty cool.

BrandyBoy72

"Whatever can go wrong, will go wrong" Murphy's Law seemed to hold true recently, at least in the Bansbach household. This weekend certain appliances seemed to be shutting off randomly, and under further investigation my dad found out that we blew a circuit breaker. Not only had it stopped working, but it got so hot from the resistance that it started to melt. SO, a circuit breaker is meant to shut off your power if the system is overloaded. Your power is shut off when the excess current and the resultant heat from the resistance deforms two pieces of metal in the breaker which start to "pull the trigger", when bent enough the trigger snaps two contact points apart, breaking the circuit (imagine that). So the overload from too many appliances being on would have tripped the breaker, but there was a faulty ground wire, so the high current had no where to be grounded to so the plastic started to mel

 

P.S. something also went wrong with my mom's car's engine, it was stalling so we had to take it in to get fixed, and now we have a loaner car. So if you see me scootin' around in a big black chevy silverado, that's why.

BrandyBoy72

 

 

Video 1: “Beliefs That Make You Fail… Or Succeed”

Beliefs that make you stupid:

a)

1. Learning is fast

2. Knowledge is composed of isolated facts

3. Being good in a subject is a matter of inborn talent

4. I’m really good at multitasking

B)

Which of these beliefs resonates with me?

I sometimes think that I can learn things really quickly, that I don’t need a lot of time, or as much time as someone else to understand a subject.

 

c)

Metacognition: A student’s awareness of their level of understanding of a topic.

 

Video 2: “What Students Should Understand About How People Learn”

 

a)

What is the most important factor in successful learning?

1.  The intention and desire to learn

2. Paying close attention to the material as you study

3. Learning in a way that matches your own learning style

4. The time you spend studying

5. What you think about while studying

B)

Deep Processing: Really understanding a topic by connecting new ideas you learn to prior knowledge of that topic and making the learning experience unique to you, helping you to have a better understanding of a topic.

 

c)

Things that help learning:

1.  Minimising distractions; maximising focus: It is hard for me to work in a room full of people or if the environment I am in is dirty, so I need a neat quiet place to work efficiently.

2. Developing accurate metacognition: For me, actually think about what I am learning and doing rather than just doing it to get it done.

3. Deep, appropriate processing of critical concepts: Think about things in the way they were meant to be used, If you only have to memorise something, then memorise it.

4. Practicing retrieval and application: Make sure I can recall facts and actually know how to use what I know, which I feel I can do.





 

Video 3: “Cognitive Principles for Optimising Learning”


 

a)

1. Elaboration - not being vague; relate beyond yourself; association: Take better notes that aren’t just keywords without definitions or connections to other things.

2. Distinctiveness - set unique concepts apart from others: Make sure to know the differences between different equations and what they are used for.

3. Personal - relate what you are learning to your own life: this sounds like what we will be doing in the blog posts, sounds like fun

4. Appropriate retrieval and application - use what you learn in specific and deliberate ways: when working on problems know what is needed to complete them.

5. Automaticity - practice something so you can do it without conscious effort: remember equations so I don’t have to constantly go back to the reference table

6. Overlearning - study beyond the classroom, knowing information to where it can be recalled easily and quickly: learn the reference table

 

Video 4: “Putting the Principles for Optimising Learning into Practice”


 

a)

1. What is metacognition? Awareness of your own learning and knowledge

2. In the video how did the teacher test for metacognition? He compared the amount of questions the students thought they would get correct to the amount they actually did.

3. How does poor metacognition hurt academic success? People can think they know something, so they don’t practice it and don’t get better.

4. Why would metacognition that was good in high school be bad for college? College requires a higher understanding of topics and not just quick recollection of facts.

5. What are differences between shallow and deep processing? Shallow processing would be if you memorize isolated facts, when deep processing compares topics to one another.

6. Name a task you already do where you use deep processing - I use this in mathematics to use what I already know to understand a new topic.

 

B)

How do the tips for taking notes in class apply to video lessons?

You have to take notes on the video lessons, it is easy to just get caught up in the talking and not think about what is actually being said. If you don’t take notes and use deep processing then it is very likely that a topic you are learning will not stick with you.





 

Video 5: “I Blew the Exam, Now What?”

 

 

a)

What should you avoid if an exam goes poorly?

Avoid Panicking or going into denial

 

B)

What should you do if an exam goes poorly?

Be honest with yourself and examine how you prepared for the exam. Review the exam. Compare errors with notes taken. Talk to your professor. Examine study strategies. Develop a plan.

 

c)

Helpful strategies to raise your grade:

1.  Commit time and effort

2. Minimize distractions

3. Attend class

4. Set realistic goals

5.  Don’t begin to slide

6. Don’t give away points

BrandyBoy72

Wow, look at me, senior year in the supposed "hardest class in the school", I'm supposed to be the "best of the best", the "smart kid". Well maybe, that is a nice title, but I don't think so - I'm the same as everyone else, except at one point I missed the memo that school is hard. I never really noticed when it was that I started enjoying math and science, guess I just had nothing better to do. And those things are definitely my strong suit, but that's kinda boring to talk about. Other things I like to do are sports, I really like being active and getting out. I "run" track (I do pole vaulting - not that much running involved) and recently I've joined cross country (lots of running involved). I'm a boyscout and I enjoy going camping on a regular basis. Boyscouts is really awesome despite what most people think, you get to hang out with your friends and learn some pretty cool stuff, yeah tying knots, but also important life skills. I myself feel more independent and outgoing, and I have seen shy and quiet kids turn into great people because of scouting. Also we go camping which is fun.

Why I'm taking physics is not much different from the reason I run, I think It's fun I'm crazy I'd be bored without it I'm crazy. That and I really like pushing myself to see if I have a limit. From this year I would really like to see just how difficult physics can get, because last year was hard, but I think I managed to get by with minimal effort while still keeping up with the rest of my life. This year I am really excited to try something new, no idea yet what it will be, any suggestions? Even though I am looking for more to do, I am already really busy, with school, sports, boyscouts, work, I am all over the place, and I am worried it might be too much, but oh well, I'll manage.

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