Balanced and Unbalanced

Situation A (below) is a Balanced Free body diagram. It is balanced because all the forces (friction, Fapp, normal force, and gravity) "balance" each other on all sides. Horizontally the force it has the same net force, (between friction and Fapp) and vertically it has the same net force. (Norm and gravity)

Situation B however shows something that is unbalanced. This object is unbalanced because there is friction effecting the object, but no force going the opposite direction with the same amount of force.

Free Body Diagrams

This free body diagram a shows an object. This object could be a chair, a box, or some other thing. I'll say a box.

The forces shown on the diagram are Gravity, Friction, the normal force, and Fapp

Gravity is in the object Because objects always have gravity. (We will assume the box is on earth...)

The normal force is there because the box is actually on a table. The normal force is shown when an object is on a surface because it can't fall or accelerate down.

The Fapp force is there because there is a constant force pushing it to the right. 

The friction is there too, and since it is only "half" of the Fapp, the box is moving.

Vectors and Scalars

Scalar only has size, while Vector is Direction AND size. 

An example of a Scalar quantity is Time.

An example of a Vector is a change in temperature.

Four Forces

I was absent. I will get the notes when I get the chance.

Acceleration

The difference between a sports car and a school bus going from a complete stop to 30mph is huge (like the bus) because the amount of time it takes for the sports car to accelerate to 30mph is a lot less than the bus for many reasons. The bus was meant to hold large amounts of people, but not to race some sports car, which are made to be faster. The acceleration of the sports car will also be faster because they are better with wind resistance then a huge block with 30 people inside of it...

By the way,

GUESS

The five steps for GUESS

G- Given

What information is in the problem? List it. Especially important for variables and units

U- Unknown

What do you need for the answer? What's the variable you need in order to state the answer?

E- Equation

Over here you put the formula you need. 

S- Substitute

Put all the variables and units you have from the Given into the Equation.

S- Solve

Solve it all to get an answer. Make sure you show units, and make it obvious what the answer is by circling it or something.

Back in middle school we didn't have any formula for Science written response questions.... But for ELA we had Real, and for math we had Ray. These were awesome for their subject, but really really bad for physics. I'm glad I have one for physics now.

Speed and Velocity

Speed is a distance you travel in a given time.

Velocity is speed, but in one direction.

An example of average velocity is how slow speed check thing in my dad's car is when he drives his stupid van, (I want to get a pickup truck so I'm not one to complain though...) and another example is how fast it goes when my brother drives. 

A example of velocity is how fast said speed gauge goes up all at once. Another example is how fast the milk falls to the floor. No one picks it back up so it's a 1 way trip.

Distance vs. Time

What we did in class was have a measuring device measure out distance away from it, and how long it takes to get there. It basically measures speed too because if you go really fast away from it, it would be steep. 

This could be helpful in class because we could use it for cars, and also understanding it probably helps us understand other concepts throughout the year.

Metric Units

3 things in my home that are in metric units are:

- A carton of milk

- Bottle of Water

- Box of Froot Loops

The first 2 are in metric probably because they hold liquids. 

The third one Is in metric because Froot loops is the coolest thing in the world. It's really yummy.

(This was also uploaded late because I wrote it in my notebook, and forgot to post it on the blog)

Estimating Distances

The front of my house is hard to measure because I live at a corner. Regardless, the front of the main entrance is probably about 8 meters?i think this is reasonable because of how hard it is to measure my house, and because my house is pretty big.

(Below is my house of swag n swag)

(This was uploaded late because I wrote it in my notebook, and forgot to post it on the blog)

Distant vs. displacement

Distance- how far you go, or the total length travelled.

Example: I fell down a 5 meter hill. I then ran back up, and fell again. What do I have: 15 Meters Travelled, and a headache. 

Displacement- the distance from the starting point, and where you are now.

Example: I ran down one block, ran down another, and came back one block. My total distance is 3 blocks, but my displacement is 1 block because I am one block away from my starting point.

Yay

Distracted Driving

Distracted Driving is bad because a distraction such as texting or drinking delays your reaction time. This means that it's harder for you to take notice of your surroundings, and at higher speeds, makes it easier for you to hit someone or something.

I've been in a car with a distracted driver before. They were texting. It bothered me because the driver always does this. Although this makes him a "pro", there's no reason he can't just wait 2 minutes, arrive safely, and then send his damn message. 

September 18, 2014 - Reaction Time Homework

Reaction Time:

Reaction time is the amount of time it takes someone to have a reaction, or reflex to something that happens. Some examples are a ball being thrown at them, a ninja karate chopping you, and in the case of the matrix, bullets being shot at you... (But in real life you can't "slow time" or use the matrix to dodge bullets)

One example of reaction time in my life is from horror games. (Which I play a lot.) Most of the time, something creepy pops out of nowhere and scares the living crap out of you. After this, you have about 0.5 seconds to pull yourself together, and run the hell away.

Another example of reaction time in my life is when someone decides to annoy me and throw a football at me. (Or really in this case, and type of ball.) I have to quickly react to where it's going, and move the heck out of the way because there is no chance of me catching said ball. Sometimes there's no chance of me getting away in time... In which case I have to try to catch it. Unfortunately it usually (95% of the time) ends up hitting me in the face.

A third example of reaction time is when the new season to an anime I watch (namely my little pony, Pokemon, and dubbed Japanese anime), or a new game came out. I have to quickly figure out how to get to where I need to go to get the game/watch the animes, and think of ways to prevent people from bothering me when I play the games or watch the animes.

One last example of reaction time in my life is when I go to school and the teacher walks in, asking for the homework from the night before. I have to quickly run out of the door, or think of an excuse.