Modeling Acceleration

Physics homework for 10/21/14:

Tuesday, October 21, 2014

Tue Oct 21 - "Modeling Acceleration" Blog Post

Find a picture of a model of acceleration online. Provide the link to the model and explain how it shows acceleration.  Is it a good model? How can you tell the difference between different accelerations with this model?

Today in our physics class we modeled acceleration in three ways. We modeled it through a formula, a strobe diagram, and a graph; specifically a velocity vs. time graph. Some variables like velocity can be modeled this way, but not all variables I believe. Strobe diagrams specifically show the motion of an object, formulas show the relationship between certain variables to achieve a specific answer. It also models acceleration through numbers and operations. Graphs model acceleration by plotting out data to show a progressive acceleration. 

Now, I will explain the first acceleration model only. I posted the other acceleration models just for reference. Also, side note just in case anyone needs help (I doubt you guys do need help with it though since you're all smarties): if you want to post a picture in a blog post and have it show in your post you need to either click the little picture icon that shows up while you are typing the draft of your post (the icon highlighted in yellow is the little picture icon in the picture I added below this paragraph). Click it and you should be able to navigate from there. If not, Google's your best friend guys, Google will always help (or I will try and help if anyone wants to ask :D).

OR just click on your photo, but don't let go of the button. After that, continue to hold down on the button and drag it to your Blogger post tab and drop it in your post. This works best on a laptop or a computer - not a mobile device. Basically go to Google, find a picture, click on the picture and hold the button down, drag the picture to your Blogger tab, and drop it in the text box where you type your post.

Okay, now onto the actual physics! 

Let me copy the top photo down here so you guys can see it better 

Sweet, huh? This model shows acceleration through a strobe diagram. It does so by drawing the running girl relative to each part (a,b,c, and d). By "relative" I mean the artist drew the girl at a specific position in the model to match up with the other pictures in the model. Plus, while a and b don't necessarily show true acceleration and more so show the girl starting and running at a constant velocity, parts c and d show velocity by showing the girl at different and not constant positions. The girl is accelerating and acceleration deals with a change in speed and/or direction. The girl's speed isn't constant here so it changes! How do we know? Each part of the part doesn't show her moving the same distance each time, she changes her speed each time therefore changing her distance. For example, in part c the girl runs a bit forward, then a little more than that, and then a lot more than that, and so on and so forth. And the strobe light takes photos at a constant rate, it will flash however many times in a certain amount of time consistently so it captures how much the girl traveled in a given amount of time consistently and not randomly.

Okay so it shows acceleration, who says it's a good model? Well, I say it's not a bad model. Maybe it's just me, but even though the diagram looks relative to each picture, it doesn't look entirely relative. For example, the girl's starting position looks a tiny bit different in each photo and the figure doesn't meet up too well when you compare it to some positions in the photos. But it might be me, either way it's generally a good model showing acceleration, and you don't necessarily need relativity to model acceleration. It might be more accurate, but I mean either way picture c and d both show acceleration nonetheless. They are also good because they fit what we have been doing in class, they look like our models just with a person instead of a vehicle and Ms.Reid is most likely looking for this. Plus her models are awesome in my opinion. This model is also good because it shows a change in velocity throughout a similar period of time. And it shows different types of acceleration (negative, positive, and constant but I don't think b counts since her direction nor her velocity changed). It also shows something we can relate to or easily visualize and remember. Say I'm in class even and I need to remember acceleration visually because I'm a visual leaner, well I could think of me running to maybe a busy street or maybe me running away from a rabid zombie and remember acceleration. Or I could imagine cars zooming away or slowing down. Either way it is quite a good reference. The model also kind of shows the movement of a person in front of, say, a motion detector, and we could picture what the graph would look like. Plus, it's very simple and very easy to replicate. Sweet and straight to the point.

Now, how can I tell the difference between accelerations with this model and even in this model when I mentioned different types of acceleration? Simple, I just look at the distance between each position and see how they compare like all of you smart cookies.

For example, in part c I see that the girl didn't move much between her starting position and her succeeding position (her next position). But then from her second position to her third position she moves a bit more forward. And this goes on and on with her moving more forward each time. I realize that this is positive acceleration because she is going a farther distance within the same period of time each time meaning she is picking up her speed. And that's true, right? If I cover more distance in say one second than I did before in the same amount of time I'd be picking up speed. I can't travel more if I go the same speed or a slower speed.

And part d shows her going at a negative acceleration because she slowly covers less distance within that time. If she covers less each time she's losing speed. I can tell the difference between these two accelerations by noticing how her distance changes each time. This will help me point out different types of accelerations when I look at other diagrams too because I'll know to look at the distance covered and to observe how she is speed-wise.

Let's all turn into bunnies!! (Just kidding).

Good night everybody :DD!!

--Ooviya