Test Corrections

^ represents the delta change sign because I don't know how to get a triangle

I don't have a blog of the kinematic equations or one about parabolic motions mainly because of confusion. At the time of learning, it's difficult to reflect and do a quality blog when I was confused because I had no idea what to write. But now that we have had a test, it's easier for me to reflect on this because there is something physical there, where I can explain what I did wrong and what I didn't understand.
So for number 15
The problem is
A diver running 3.6 m/s dives out horizontally from the edge of a vertical cliff and reaches the water below 2.5 s later
How high was the cliff?
What I did?
I tried using the a=^V/^t
And then I plugged in ^v in the 1/2a(^T)^2 +vi^T equation
which doesn't really make sense because initial velocity is definitely not the same thing as change in velocity. It is fair to assume that the initial velocity is 0, so you just plug the info you have into the change in position equation, and you would get out around 31 meters for your answer. 
How far from the base of the cliff did the diver hit the water? 
I can't even understand my work here and I don't know why I got it wrong. I feel like a lot of times with these problems I try to complicate it, and I think it possibly can't be that simple when it is. Basically, If you go 3.6 m/s and there are 2.5 seconds, you just multiply 3.6 by 2.5 and your answer is 9 meters.
17
A soccer ball is kicked from the ground and lands on the ground 2.2 seconds later
What is the initial vertical component of the ball's velocity
Once again I don't understand my work. But I overcomplicated it again,
Basically if you are trying to find the initial velocity, you can assume the position is 0, and then solve from there. You plug it into the the 1/2at^2 equation and your answer is around 11m/s
How high does the ball get above the ground
I didn't even answer this question, but since my vertical velocity was wrong this would be wrong too. Basically now you would plug in the vertical velocity in the equation and get out the change in position. But, you would need to use 1.1 seconds instead of 2.2, because 2.2 would give you the end results...since it is a parabola the maximum height would be at half the time.
If the ball was kicked at an angle of 55 degrees above horizontal, what was the balls total initial speed?
Once again, I got this wrong because I had the wrong vertical velocity. I did do the right process with the wrong velocity, but that doesn't matter. If i did the same thing, except using 11m/s, I would get the answer 13.4.
Basically, on a lot of problems, I mess up the process on one thing and then the rest of the problem is completely wrong. So i need to take my time and think what I am doing wrong.

Friction

We've started the topic friction, which was negligible up until now. I think friction has always been something we've known about, but never really understood. In class, we did a lab where we tested what objects and materials are affected by friction. We had tested how shape, speed, surface area, and material effect are affected by friction.
Results
Shape- No Relationship
Speed- No relation
Surface Area- No Relation
Material- Yes
Force- Yes

The one that blew my mind here was the results of shape. I feel like personally, in my mind a ball would roll down a hill much faster than a box would. But typically, in a real life scenario, a ball and a box do not have the same material. In this lab we used the same material, same amount of force, and saw the amount of force applied remained the same. I feel like when I think about it now, the same material will create the same amount of tension with whatever object, so shape does not really matter. I think the rest of the results were fairly predictable. My group decided to do the force lab differently than other groups by changing the angle at which the object was dropped from where as others used a force o meter.
We were introduced to an equation

We were given a packet, and those problems were fairly simple to do. The idea of static and kinetic friction came up which was something I've first hear about, It the idea that to get an object going it requires force but it might not move, but when it does move you apply the same kinetic force.
Overall, I like the friction problems and I find them fairly easy to do.

Vectors

I feel extremely behind in physics especially with vectors because I've missed 2 classes where we have talked about them. I have only been present for the class where it took 50 minutes to answer one problem. This is definitely something I need to spend extra time on, I've done only 2 problems of this and missed extra class discussion.

I am going to watch a video explaining.

Before video: A vector shows direction in which something moves

https://www.khanacademy.org/science/physics/one-dimensional-motion/displacement-velocity-time/v/introduction-to-vectors-and-scalars

So my idea of a vector was basically correct. So a vector is direction with a size (or magnitude but we haven't used that word in class yet). So if an object moves 15 meters to the right this a vector quantity. I feel like its fair to say, you can group displacement, velocity, and vectors all in the same category. The video also touched on scalar quantities, which I am unsure of if we touched in class. Scalar quantities would be just the distance traveled without the direction. So you can group distance, speed, and scalar quantities together. 

From class the one day I was here we used the pythagoreum theorum and sin/cos/tan to find vectors. I definitely need to do some practice problems from the packet we've done, because I don't have enough experience with this to feel comfortable. I feel like I understand the concept, it's just practicing ways mathematically to figure it out.

Looking at vectors a few weeks down the line<It's easier to grasp. I think what had confused me before was the idea of changing the axis, but this works when trying to solve problems with diagnol vectors. It took me awhile to understand this, I even had to go in for a lunch session, but I think now it is fairly straightforward. 

Beginning of IB Physics SL :)

So far our class has been just reviewing concepts from freshman year, nothing all that new yet. We've covered position, distance, displacement, speed, and velocity. We've mentioned velocity here and there, but really haven't delved into it as much as the other topics mentioned. So i'll just go over a quick run down of things.

So to the left you're looking at a very basic position vs time graph. The topic of comparing position, distance, and displacement came up. So in this example, At 5 seconds:
Position: 50 m
Distance: 50 m
Displacement: 50 m
All of these came out to be the same in this scenario, BUT THIS IS NOT ALWAYS THE CASE!!!!!

So before I dive in deeper, I think it's a good idea to define the terms I've used so far.

Position- Position is the location the object is at. So in the graph above, at 5 seconds the position is at 50m.
Displacement- Displacement is how far the object is relative to the reference point. Direction matters!
Distance- Distance is the amount traveled in total regardless of direction.

So here's a question: What's a scenario where position, displacement, and distance are all different? 

So basically here's an answer. Obviously this isn't the only answer but the general idea applies. Basically to answer this, your starting point and reference point need to differ and at one point you need at least one positive and negative slope on your graph.

So in this graph specifically, the intervals on the y-axis go up by 20, and the x intervals increase by 1. 

I will evaluate the graph at 6 seconds.

Position: 20 m

Displacement: 0 m

Distance: 80 m

Also, since we already have a graph above, we might as well knock two birds out at once and talk about velocity and speed as well.

Velocity: displacement/time

Speed: distance/time

So for the example above

Average velocity: 0/6 = 0 m/s/s

Average speed: 80/6 = 13.3 m/s

Just to tie in acceleration a little, basically the slope of a position vs time graph equals velocity, and then the from the slope of a velocity graph you can get acceleration. 

 The topic of linearizing came up, which confused some. And i'll admit, last year in chemistry we were just handed a worksheet and we were told to linearize without really any discussion on it and I was just lost. But with a little research I knew what it actually meant, and the concept is fairly simple.

 
So basically, this is what helped me the most. If it's still confusing after this, I recommend watching youtube videos that can clearly explain it in a few minutes with examples and whatnot.

We also did a lab which was pretty fun. So basically we were given a boiling flask that was 500 ml, which looked like this:

So basically we measured, and in our flask only the bottom circular portion was 500 ml, and the neck was 50 ml. So our task was to basically record the height at a certain amount of time. So what we did was we did a scale that 1 sec = 1 ml. And since there was 550 ml, theoretically, 25 ml with 22 trials should fill up the entire flask. So basically, we would put in 25 ml of water, which would also represent 25 seconds, and then we would measure the height of the water with the ruler. We ended up having to do 24 cups of 25 ml, due to imprecise measuring (we literally used like 8 different beakers and graduated cylinders because of the time crunch) but this was pretty insignificant because it did not effect what were analyzing. Basically, when the flask is thinner the slope of the position vs time graph would be steeper, and then at the wider parts it would be less steep. What was really cool about this experiment, was that if you turned the flask sideways that's what the velocity vs time graph would look like. I just thought that was really cool and worth sharing about.

FRESHMAN YEAR: a blog i started but apparently never bothered to finish

Dear Blog,
Sorry for neglecting you :) The last post I wrote was back in December when i was still a bit confused on acceleration. Not really that confused anymore, so here's a quick run down of things:

• Speed up, slow down, or change direction
• Slope of velocity vs time graph
• or (this is what I do)...final velocity minus the initial velocity divided time gives you acceleration
• Units/s/s

There is much much much more. That's just what came to mind. Now to current trends: forc. So basically ive learned...(will finish and edit tomorrow) 

FRESHMAN YEAR: Cart on a ramp

All the graphs we've encountered so far have had a constant velocity. 

constant velocity graph

When we set a car on a ramp we have seen that the velocity was no longer constant. The graph looked linear. So it is a constant increase in velocity.

 

So as you see, the two graphs are very different. This graph shows that in every single second the velocity is changing. I really wasn't expecting the graph to look linear because I thought it wasn't possible. Though the two graphs look different, I'm sure you can still calculate the velocity the same way. I think we have to go more in depth with this topic. I remember that Mr. Battaglia said something about acceleration at the end, but i'm not entirely sure what it was. So my question: is the second graph a model for acceleration or is it just simply velocity constantly increasing?

FRESHMAN YEAR: All Things Velocity

Velocity: Speed in a direction (displacement/time)

Speed: distance traveled over time

Position: The location of an object relative to a reference point

Displacement: Change in position

Distance: total amount of travel

Over the past few weeks we've been trying to understand velocity. As you see from above, velocity is speed in a direction. One of the huge questions our class ran into was if it is possible to go from a Position VS Time graph to a Velocity VS Time graph. The answer is yes. Imagine a velocity graph with the velocity of 4 and time increasing by one second. Now imagine a position graph with time increasing by 1 second as well. So, since the velocity is 4, the graph will increase by 4 every second. Also let's say you have position graph, and your position is 12 feet at 3 seconds, if you do the math velocity would be 4. We also discussed you don't have to be at your reference point/position for your velocity to be 0.

  

  In the graph above you see that position increases 5 meters every second. Your velocity would be 5 up until 5 seconds. I found that by dividing position by time. After 5 seconds your velocity would be 0, since there is no change in position. 

Other things we discussed:

New Class Rule: Don't use X or Y to identify the axis' because in the scientific world X represents position and it's just confusing.

Position, displacement, and distance can all be different. If i'm being completely honest, i'm still a bit confused on displacement.

Distance: 200 meters

Position: 0 meters (from reference/starting point)

Displacement: Would it be 0 or 40? Or am I completely wrong and it's something else? Honestly my confusion is coming from not being completely clear on whether we're measuring change in position from the reference point (0) or change in position from the previous time interval (the difference between the change in position from 40 seconds to 50 seconds).

EDIT: Today in class my question was answered. So, that means the displacement would be 0.