Week of December 7, 2009

This week in Science i continued learning about forces and their effect on the objects in the world around them.

Thing Learned: drawing force diagrams

Learned By: identifying all of the forces that effect an object of interest and the direction that they are pushing

Thing Learned: which way an object of interest will move

Learned By: identifying the unbalanced force effecting the object and which way it is pushing

TL: that delta V arrows and the direction of the object (like a ball or car) go in the same direction

LB: drawing force diagrams and comparing them to the delta V arrows on motion diagrams when they are drawn

TL: that two balanced forces cancel each other out and make the object of interest stay still

LB: splitting into two equal groups and pushing on opposite sides of Mr. Finley's car

TL: scales measure the force of someone/something applied on them (weight not mass)

LB: watching Amy and Amanda do an experiment on You-Tube

TL: people weigh less on the earth's moon (or other small planets or moons) than they do on earth

LB: comparing the earth's mass to the mass of other planets because the mass of the earth is bigger so the pull of the earth is stronger

TL: the greater the mass the smaller the acceleration

LB: having Kathy and Laura pull Mark, JR, and Aage in a cart

It is important to know these things if you go into physics in college or high school and also so you can just understand who will go faster down a slide; you or your little brother, and so you will understand that you don't actually get fatter in an elevator.

Week of 11/30/09

This week in science I learned about forces and their effect compared to other forces. Like the force of your hand against the forces of gravity. I learned how to make force diagrams. You make a dot and label it the object of interest. like a ball or house or frame. Then you draw all of the forces that effect the object as arrows. The longer the arrow, the stronger the force. You label the arrows the F (force) of an object on the object of interest. I also learned that all objects and only objects can exert force.

I learned these things by having one person hold two thing in their hands, like a bowling ball and a basketball, and ask them if they are exerting more force to one of the objects. I learned about the forces by drawing pictures of the situation that is in the question. Then you draw arrows on the picture to explain the forces. I learned what length to make the arrows by knowing that if the two arrows are equal and the equation equals zero that the object is being held steady.

It is important to know these things because forces are all around us and so we should know what a force is and how they work. We also should know about which things exert forces so we can predict how an experiment is going to work. Also, if you will eventually be taking physics then you should know all about forces and how they effect the objects around them. Forces are everywhere, so you should know about them and how to factor them into a situation. That is why you should know how to draw a force diagram.

Week of November 16, 2009

Thing learned: predicting when two things will crash

Learned by: making graphs, tables, and functions.

Thing learned: coming up with speed per unit

Learned by: delta position divided by delta time or x2-x1/t2- t1

Thing learned: when two things are a certain distance apart

Learned by: making tables and/or graphs

Thing learned: relationship between speed and velocity

Learned by: |v|= speed

Thing learned: "dot diagrams suck"

Learned by: they don't tell you enough about the motion of an object

Thing learned: making motion diagram

Learned by: doing problems like the one with the motorcycle and the moon. You can make one by adding arrows, an origin, positive and negative directions, and labeling ( V1, V2 ect.)

It is important to know these things so that you can read graphs and describe motion. If you know this than you will be able t accurately display data to anyone who wants to read it. You can show it better than a dot diagram or picture. Scientists use this information to make roads and speed limits. You also need to know this if you are a pilot (when two planes will collide) or astronauts. If you are making cars you need to know this stuff. And if you are coming up with a speed limit you need to make sure that cars will not flip over or skid when making a turn.

week of November 2, 2009

This week in science class i learned about graphing and describing data and writing functions.

I learned these ideas by:

Drawing trend lines to explain the graph. A trend line points to the general direction that the points are going to. They don't need to be exactly on the points but they have to have an arrow at the end.

Writing Functions. To make a function you write the dependent variable and put the independent variable in parenthesis next to it. Then you multiply the physical quantity number by the two units and then by the variable.

Using variables as numbers we don't know. This is hard to explain but it is like using a letter in place or a number that we don't know, like in algebra. For example, the starting time of a jogger could be t1 and the ending could be t2.

Coming up with variable expressions. For example, if you want to find out how long the jogger ran for you would have to do t1-t2. It is hard to figure out these expressions when the questions and situations become more complicated.

It is important to know these ideas so you can make graphs if you are a salesperson or you are trying to convince someone to do something. KNowing this stuff will help you express your data once it is collected, so you can display it in a way that is easy to understand and work with. It is good to find patterns in your data so you can make predictions about what will happen (like people do when choosing stocks). It helps to know the independent and dependent variable in your data.

Week of October 26, 2009

I learned about showing motion in tables and graphs.

I learned this by doing several experiments.

We drew a picture of a car activity and labelled negative and positive sides. Then we learned how to make dot diagrams and turn those dot diagrams into charts. (position vs. time)

We also learned to switch the axis's. When something is headed toward the negative side the graph needs to be adjusted. We can draw this graph by making a big plus sign and labeling the positive and negative sides of the y and x axis. Then you draw your graph going down into quadrant 4, or the positive x negative y box.

We experimented with how to draw graphs of things not moving and how to make graphs curve. We also made our own situations to pre-existing graphs.

Then we learned how to compare dot diagrams and graphs. We learned about positive and negative motion. when a line on a graph is going up, it is positive motion, when it is going down it is negative motion.

Lastly we learned to make index's for different kinds of popcorn brands to find out which pops fastest. An index is a number that helps to compare things. It is similar to a ratio.

It is important to know these things because then you can show how things are moving and discover important things like when two asteroids will collide or two objects. Also, this will help you understand and help you make graphs in math class, when you have to do similar things. Overall, I think it is important to know these things to explain and understand motion.

Week of October 19, 2009

This week in science I learned about motion.

I learned these ideas by conducting multiple experiments.

First, was the telescope experiment where we made a paper telescope and held it up and kept something in focus. The way I was holding it was my initial orientation. Then we followed Mr. Segan run with the ball while keeping the ball focused in my telescope and discussed how we know something is moving. Something is moving when the background changes, you have to change position to keep it in view, and when you compare it to something still.

Next, we did movement with observers. Every observer sees movement a different way. For example, a person who is in the process of sitting down will see a person who is standing straight as going up. Or a person in a car driving away will see a person standing still as getting smaller and farther away, when in fact they are not moving at all. We did an experiment with Someone on the side walk, two cars (one fast one slow), and a person on a bench, then we discussed how each person would see the movement of the cars.

Then, we learned how to describe movement with different directions. We learned that left and right does not always work because people face different ways and everyone's left and right are different depending on where they are standing. We tried to use cardinal directions, but that is hard to do if you do not have a compass. Then we decided that a coordinate graph setup is best with an x and y-axis, and positive and negative sides of each axis.

Lastly, we learned how to measure the movement of thing like cars by coming up with a time interval (like 2 seconds) and marking where the car is every two seconds. You can mark where the car is by putting down a piece of tape and marking with a marker or a cube where the car is every time interval.

These ideas are important to know so you can accurately explain the movement of objects and their location. This will help you communicate with people and measure where things are or how fast they are going. it is good to know this stuff when you are driving or making a model car. Also, to explain where a boat or car is and which way it is going to a friend facing the other direction or all the way across the street.

Week of October 12, 2009

  Something that I thought was confusing about light is how the eye sees the image.  I know that your eye takes in rays in the pupil and turns them.  But how do the rays turn?  And how come the rays only go into the pupil and not your whole eye, its not like your eye can attract light?  I figured out that your eye is like the cardboard experiment and the rays can only go through the hole, and they flip just like the candle flame.  I still do not understand the reason why the rays only go into your pupil and i definitely do not get how the rays can travel all the way up to your brain without being stopped.

I understand how light travels very fast in air and slower in water.  Since water is denser than air it refracts and the water waves are closer together.  The running thing made sense and helped me understand it more.  LIke when Jackie, Laura, and Perry had to weave through everyone they couldn't run as fast as they could normally.