Distance vs. Displacement

Physics homework for 9/30/14:

“Distance vs. Displacement” Blog Post - Describe distance and displacement IN YOUR OWN WORDS (do not write the definition). Give at least one example of each that you noticed throughout your day!

Tuesday, September 30th, 2014

Distance and Displacement

Today in class we learned about distance and displacement and we distinguished the differences between them. We also compared them to observe them and to better understand them. Additionally, we also took notes, tested our knowledge on the matter, and talked a little bit about the topic. 

So to begin what is distance? Ms.Reid gave us this definition for distance or, "d", which is the variable for distance, distance is "the total length traveled." Sounds pretty straight forward, makes sense right? But that's the notebook definition, what is distance in my own words?

Distance to me is the entire length something has traveled from point A to point B. It is usually always a number with a certain unit describing it. It also is kind of like a measure of travel or how far you have traveled in all. It is the amount of space between two points usually, but sometimes it does not have to be between two points specifically. It can be distance over days in different places. Or between separate sections of travel, distance does not have to be entirely constant. Also, when I think of distance I think of traveling or movement, distance has a fair magnitude too. You usually do not hear about small increments of distance, you usually hear about things like miles and what not when it comes to distance.The unit used for distance is our class is "meters" or "m", but the units can vary, in science the units are usually metric though.

Distance also has a formula: d = t x v (I believe). And you can manipulate this equation to get the equation for other things as well. (T = time and v = velocity, "t" also is usually represented as "delta t" or "change in time"). Finally, distance is a scalar quantity, it has magnitude but no direction. Distance is specifically a scalar quantity and its counterpart is displacement. Maybe it is not exactly a counterpart; but it has what distance does not have, direction. Displacement is a vector quantity that has magnitude and direction.

An example of distance and displacement is say I walk 10 steps forward, what is my distance and what is my displacement?

My distance is 10 steps and my displacement is 10 steps north/forward.

Now, displacement is a little more than just magnitude and direction. While distance is the total amount you travel or the total amount something travels, displacement is "the difference between your starting position and your end position" (by notebook definition). So you could travel a distance of 20 meters, but with displacement 20 meters might not be your answer. You have to worry about direction with displacement and it is the DIFFERENCE (subtraction) of your starting point and your end point. 

If I go 10 steps north then 5 steps south, what is my displacement? 

Well, the difference between 10 - 5 is 5. And with displacement I keep the bigger magnitude's direction so 5 north. (Little arrows are used with the notation, but I do not know about them too well yet and for now it is best that I keep it simple).

Displacement to me is change in position and/or the difference of position. For some reason my grasp on it is weird, but I understand the basic idea of it. The variable for it is "delta x" or "change in position." The unit used for it is also meters. And unlike distance, displacement can be negative! And again, it asks for the difference, not the total which are opposites. 

Examples in the Real World

Honestly there are so many examples of each quantity, but today and every day I travel a distance to the school and back. I am also told my distance traveled on a treadmill. We see cars travel a certain distance, etc. Every day we travel a certain distance, but our displacement is a little different.

When I think of displacement I think of sometimes being in formation during JROTC. Sometimes the cadets need to step forward or backward a certain amount and we have similar displacements so that we can order ourselves properly. I also think of traveling back and forth between places like from my home to school. Board games also have displacement like when you choose a card and have to take a few steps back. Also, remember in all of these examples the objects or people need to travel a certain distance and it all needs to travel in a certain way. In a board game, I cannot just send my piece four steps forward, the game card usually tells me to go four steps backwards and/or forwards or something. 

Distance in real life is also observed in traffic and in other scenarios, displacement is seen a lot in similar scenarios but also in the sea and in the mountains. People can descend far down or ascend high up. 

Today specifically I probably added up a huge distance of walking between classes, but a small displacement depending on my position and what not.

Buonasera amici! :D

(ALSO: Note to myself (try to study distance and displacement a bit more), I love Khan Academy and it has great physics videos so do use their website if you are still confused about anything for whatever reason). KA: https://www.khanacademy.org/science/physics + https://www.khanacademy.org/science/physics/one-dimensional-motion/displacement-velocity-time/v/introduction-to-vectors-and-scalars

KA's videos are pretty simple and helpful, they're also fairly short depending on what you watch so I personally encourage others to use it and other resources if they need to. I can help navigate on there if any one would like help with that, but I am sure many people are already familiar with it.

--Ooviya

Metric Units

Physics homework for 9/24/14:

Create a blog post titled “Metric Units” - find at least 3 things in your home or your neighborhood that has metric units.  Describe why you think these things are in metric.

Wednesday, September 24th, 2014

Items in Metric Units

During class today we learned a little bit about measurements, specifically metric measurements. Metric units in general are very easy to use and are even favored over customary units by people living in countries and places using customary units and systems. Now, while both systems have a purpose, metrics are much easier to use because they go by sets of tens and therefore they are easier to convert and they have basic concepts. For example, 1 centimeter is 10 millimeters. Simple, right? If you want to convert between cm and mm just multiply your number by ten or divide it by ten. And even if some numbers are not 10 or something, metric units still go by ten. So 55 millimeters is 5.5 centimeters. In science classes metrics are almost ALWAYS asked for. 

Customary units are not as simple and seem almost abstract to many. When converting between two different types of customary units you do not get very clean numbers often or even at all. Sure, 5.5 cm is not that clean since it is not an integer, but most customary units had many numbers after the decimal that do not go in any type of a pattern like "3.4535.." With customary units you usually multiply or divide by a certain number you have to memorize. Here is an example of customary conversion: 1 inch = 0.0277778 yards. 

Moving on though, I found three objects in my own room that have metric measurements on them. Here they are:

A Poland Spring water bottle: 591 mL or 29 fluid oz. So if the bottle is full at the right amount it would contain 591 mL in volume. Milliliters are a measurement of volume.

A single sheet of paper from a "Caliber" brand pack of paper: 216 mm x 279 mm in length AKA 8.5 x 11 inches. Millimeters are a measurement of length.

An antacid tablet from an Antacid bottle: Each tablet individually has 400 mg of calcium in it and 500 mg of calcium carbonate. Milligrams are a measurement of mass.

I tried to get different types of measurements as variation is important and as many products are not the same. Some are liquids and some are solids and some are measured by volume and some are not, it all varies.

Let me illustrate one point, almost anything can be measured in metrics or in customary units it is just that these items had metric units on them. Some products and things do not have metrics at all or vice versa, it depends. I could easily measure anything in metrics or in customary units, it is just these items already have metric units on them. And most products in general will have metric units on them. 

So why do I think these items are in metric units? Well, one reason might be because many people are not familiar with the customary units so they might need the metric units. Or maybe because having units from both systems is good for reference. Maybe since metrics are easy to use people prefer their products measured in metrics. Or maybe metrics are easier to visualize and/or think about. Also, some measurements are more practical to use for somethings so maybe these products needed the metric measurements. Each system does have its own uses and what not even though they are used for similar things.

Or maybe there are some historical/cultural reasons behind it all, maybe they have generally always been measured with metric units and they want to keep both sides of the coin or possibly they want to use whatever is best for their product. (Note: not everything measured in metrics is really a "product" I just use that word a lot because the things I found are products and because I mainly think of products when it comes to this). 

I mean a water bottle use mL and oz because it does not contain and huge quantity of liquids or anything and because maybe people need to use one unit or the other. Sometimes science and other things require these units and so people make our lives easier by converting everything for us. Maybe it is just some product criteria imposed by the government or something. But I mean some products can use small units like mm even if the product has a large quantity, but products with huge quantities do not use small units for practicality so maybe that relates to why some items have metric units on them. I am not entirely sure, but I am sure that people are not just wasting ink and stuff on it so I am glad I at least know there is a reason for it.

But that is my take on it all, good evening everyone! 

Estimating Distances

Physics homework for 9/23/14: 

Create a blog post called “Estimating Distances” - in it, Estimate the length of the front of your house.  Explain if you think this estimate is reasonable or unreasonable and why.

Tuesday, September 23rd, 2014

Estimating House Length: Unreasonable or Reasonable? 

Today we did a lab on measurements and we had a discussion about our findings and what not. We also discussed unreasonable and reasonable estimates today and were asked to estimate the length of the front of our own homes. 

I estimate that the front of my house may be approximately 4 meters wide but closer to 5 meters. 4 meters in centimeters is 400 cm and 5 m in centimeters is 500 centimeters. Also, just for reference and what not, 4 meters is 13 feet and so 5 meters is about 16 feet. So the front of my own house might be in the 10-20 ft range. Now, I could go outside and measure the length of the front of my house but I will not do so unless instructed to because if I know the exact length it is hard for me not to think about that specific length and so my estimate does not become super sincere.

I think my estimate is reasonable, at least for a house like mine. It is not huge or anything, and it is not even as big as other normal homes. Maybe it is unreasonable because the front seems about as big as the width of a standard room, but my own living room's width is just about the exact same width as the front of my house so it is not surprising to me. The length of my house might be three times the measure of the front of my house, but the length of my house is not the front of my house so I do not think it matters that much here.

With that being said, most normal houses do not have huge lengths. Even in other units, if a house is 1,200 cm wide then it is not really as big as you might think it is. Mansions might have bigger widths, but even mansions do not exceed the reasonable measurement estimates of a dwelling. Any ways, small home or not, I feel pretty good with my estimate but I might be really off since I am not too knowledgeable on the subject of measurements, conversions, and measurements of objects. I use my common sense like everyone else, but I still am not as good as everyone else is with it. Hopefully that changes as I have a physics class, but also because it is a good skill to have and what not. Enough with my tangent though, good evening everyone! 

Buonasera and buenas tardes~. :D!

Distracted Driving

Physics homework for 9/22/14: 

Create a blog post titled "Distracted Driving." In it, explain why you think that distracted driving is bad and describe a time when you were in a car and someone was distracted. What were they distracted by? Did you even notice at the time? How do you feel about it?   If you've never been in that situation, then describe what you are most worried you do when you become a driver. Why does it worry you?

Monday, September 22nd, 2014

Distracted Driving Problems

Distracted driving is definitely not a good thing, many people are told this and taught this. People are told of the types of distracted driving and given many details on what happens, but not why it is bad and not exactly what to do. We are told not to text and drive or drink and drive and it gets so cliched that people forget why it is so bad and that people do not care and think it is fine to get away with a few instances of drunk driving and texting at stop signs. Let us illustrate exactly why distracted driving is bad; but before we do that, what exactly is distracted driving?

Distracted driving is pretty straight forward; it is when you are driving and you are distracted by something else, like say messages from texting or say multitasking and doing something else while driving like doing your makeup in the mirror. Basically, it is driving while being engaged in another activity or in other activities. If you are under the influence while driving distracted it is even worse and more dangerous for you and those around you. 

This driving is bad firstly because it slows your reaction time and can actually deplete your focus and overall response time after a while. While you are say, texting, and driving you might not notice something on the road and so you react slower than you would if you were paying attention to the road. And if your texting and driving habits begin to become a huge habit it is hard to break out of it and soon enough you might actually have a hard time focusing and responding even if you were not texting and driving! That might actually be unhealthy and unhelpful on top of unsafe. It can affect more than just your reactions to driving but to other things which can lead to unfortunate situations for you even when you are not driving. 

Secondly, while texting and driving you can really only do so much, it limits what you can and cannot do and thus in turn it is easier to get into trouble. If it is harder to do certain things you might forget to use some things in your car and that could turn into problems fast as you would only really pay attention to what you could do. While driving, it is important to stay alert. You never know when you might need to use a specific control in your car even if you do not use it often. And you might accidentally make some mistakes due to your distractions.

Also, while you might get the hang of texting whilst driving after a while it still does not change the fact that it can cause problems and that it can ruin your reaction time. Even if you are good at multitasking it is better to play it safe and not put others into great peril all due to your carelessness, as harsh as it sounds, it just is unfair. It is not worth getting the hang of if you almost get into trouble the first few times. Besides, is it REALLY that much of an emergency to text someone while you are driving. At least try and be more responsible about it by pulling over or something. That might sound weird, but at least it is safe and at least it can save lives. Any ways, how badly do you really need to send that "LOL" or something? If the text is worth a reply like a text about a family trouble then again pulling over is a good idea, not continuing on your way and texting at the same time. 

To add on, it is a bad influence on others as it can cause others to want to text and drive. Some might begin to think it is okay. It might not seem like many people at first, but the people build up over time infinitesimally. Accident rates begin to go up and it is hell all around. Plus, it can make people shirk responsibility.

Finally, distracted driving is also bad because you could hurt people or even kill them due to it and it could get you into trouble whether you hurt someone or not. Is that one text really worth a life? All the police trouble you might get into? If you cannot react fast enough in a situation, it can cost a life. Your own life or someone else's life. All because of something that was in your control, all because of something that could have waited. Car accidents happen a lot, but not all accidents happen for the same reason. Some happen due to things that you cannot control like weather or an out of control vehicle about to crash into you, but you can take the power in your hands to prevent accidents from happening. Driving is a very serious thing, if you do not take it seriously it will really back fire and cause harm. It might not seem that bad, but try and find out more on the topic and you will see it is quite the opposite. In reality, it could be like you driving with your eyes closed at 55 MPH 200 yards or so; and I think we can all agree that that is NOT safe, whether you like texting while driving or not. 

Distracted Driving in my Own Life 

One time in my life where I have been in a car and someone was distracted was when my mom first started driving. My mom drove well and did her best, but like all drivers she had her fair share of problems. 

Though, one day my mom was driving my brother and I to a sort of plaza and she dropped some money or something like that at a traffic light. We were at a red light and there were so many cars moving by slowly that she picked the stuff up. But she pressed on one of her pedals accidentally or something along those lines as a result of it and our car bumped into the car in front of us. I definitely noticed what had happened and felt quite worried at first, but then relieved hearing my mom explaining her mistake and how we should avoid it and stuff when we become drivers. I still was a bit worried that we would get into more problems like that, but I knew my mom was responsible and she still is so I felt that she would do her best to drive safely no matter what.

I know I have been in some moments where the driver of the car was distracted and I cannot remember many of those moments, but even so I will answer the other two questions. 

I do not like worrying at all, I want to be collected and confident in a humble manner. But I am worried that I will accidentally make some mistakes even though I know better. Like accidentally answering my phone and talking while driving even though I do not want to do that. I am hoping I will be really intent and precise with my driving. I just want to do my best and follow all regulations. This all worries me because it can have a huge ripple effect. I could hurt people if I do not drive responsibly and I could influence people in the wrong way. I also do not want to make my mistakes while driving because on my own at least it will not have a huge harmful effect, but if I make the mistakes while I am driving it might not end so well. But I will do my best, and I am sure as long as I care enough and try enough about it all I will find my way and do well. 

In conclusion, if you don't put your phone away, Ms.Reid will drive up in front of you and REALLY get your reaction time bumped up to snuff! Pfft. Kidding. But seriously, distracted driving as well as drunk driving is a huge issue. Please think about the consequences and what not more, it could save LIVES. You do not want to end up getting someone hurt or even dead, it can really be hard to live with and it is just not a good thing.

--Buonanotte, buenas noches, and good night. Remember to drive safely no matter where you are and just in general no matter what. 

Reaction Time Physics Homework Post

Physics homework for 9/18/14: 

“Reaction Time” Blog Post - Describe what reaction time is and explain three examples of reaction time in your own life.

Thursday, September 18th 2014

Reaction Time 

Today in Ms.Reid's class we conducted a lab that involved recording reaction times. Our own reaction time was recorded a few times and another person's reaction time was also recorded. We did this in pairs and did two different ways of recording our reaction time; we used stop watches, and we caught rulers. This is the first day we have been introduced to reaction time in our physics class and we are learning about it because it will contribute to our first Chapter Challenge project where we have to create a driver's manual in groups.

What is reaction time though? In my own words, I would describe reaction time as the difference in the amount of time between when something begins and the beginning of a response. By that I mean say someone drops something and another person tries to catch it as fast as they can, when the person dropped whatever it is that they dropped the time began or the stimulation began. When the other person tried to catch whatever the first person dropped that the beginning of the response. To me, reaction time can also be how long it takes someone to react to something. With reaction time you must think fast about what you want to do and/or feel a sense that makes you want to do something, and then you must act upon that sense or want and actually execute your action. So the decision and the action both play a part in responses and reaction times.

But those are not the only things that come into play with reaction time, there are MANY factors that play a role in a person's reaction time. Reaction time can be used and seen in many scenarios and depending on the scenarios different factors can play different roles in the scenarios, but the main example used when describing reaction time is stopping a car or even just something to do with cars in general so I will use an example involving cars.

Say Ms.Reid was driving her cool, super slick Mercedes to Eastie on a really gloomy and overcast morning and she was extremely tired. All of that fog and what not from Mother Nature is just clouding up the area and her windows and she is trying to see and maneuver safely to the school. When all of a sudden she sees something and she cannot tell what it is and--OH DEAR GOD IT'S A TREE--*SLAMS BRAKES*

In such a situation any one would have to react fast, especially if you are driving and about to hit ANYTHING. But the factors here that affected Ms.Reid's reaction time were her sleepiness (technically, probably), and the weather. Now, Ms.Reid in real life would probably actually drive super fancily down the road to the school, but those things could have actually affected her driving even with her experience. Though remember that the weather and how you feel are not the only things that can affect your reaction time.

Reaction times are very important in many situations, with out it we might get into a lot of trouble on a daily basis! And with almost all science there is some math involved here and some laws of physics as well as motion concepts can be applied here. In class we recorded some times using stop watches and used basic elementary math to find the difference between our times to see our reaction times. We also found the mean of those times. The stop watches was the first part of our lab, in the second part we caught rulers as fast as we could and where ever we caught the ruler (say at "3 cm") we would record the measurements and convert the measurements into time using a graph and find the average to see our reaction time as well.

Real Life Reaction Time

We go through daily experiences that involve us to think and react fast so reaction time actually occurs a lot in our lives. 

Here are some of my own times where I have demonstrated my own reaction time:

--1. When I was in dance class we had to learn a lot of dance moves and practice a lot obviously and then we would perform. Well, with anything and especially dancing or something involving memorization and practice we can easily mess up because we are going too fast or something. Sometimes when I performed or practiced I felt super confident in a humble manner and tried to do my best whilst enjoying it and stuff. I would feel all dandy and happy inside and then I make a mistake! Once I make that mistake I have to act fast and just continue on. Or say there are some delays in playing the music or the music goes off while we are dancing; once it starts up again we all have to respond fast and keep going.

--2. Sometimes when you do not pay attention to something like cross walks and wait without looking at the cross walk you might react quickly once you see the actual cross walk go off. I know this has happened to me a lot with various things, and it is not just cross walks.

--3. Say you see something falling off or say you see something about to break or someone about to go berserk, normally you would do something and FAST. Reaction times vary with each person, but I am sure everyone would go as fast as they could. I remember my old Toshiba computer sitting on my dresser in fact and I accidentally tripped over the power cord. It was so close to crashing to the floor, but luckily I reacted fast and caught it... And I sat there for a good while shocked as all heck.

--4. An extra reaction time moment in my life. So one day going to elementary school in Woburn with my little brother we were walking on our way merrily to the bus stop close to the apartments, and we have to cross the road to get to the actual bus stop. While we were crossing I had not noticed one particular car driving fast towards us; but it hit the brakes so fast and so hard that SPARKS were made from the tires. And I was quite scared, I actually did not react by running but by trying to shield ourselves very fast. The car honked at us and we ran super fast to the sidewalk after that. Glad nothing actually bad happened but thank goodness for reaction times.

Good night,

Ooviya