A: Speakers emit sound, vibrating the ball off of it.
B: Ball falls down board and through funnel.
C: Elastic spring is pushed by the ball, and launches a toy car down a track.
D: Car knocks over dominos.
E: Domino hits chopstick to release a ball. The ball rolls down the track and hits another chopstick releasing another ball, and then hits another chopstick releasing another ball.
F: Last ball knocks over tower holding ball from rolling, then the ball is released and falls down hill.
G: Ball hits dominos and dominos hit box of cards.
H: Box hits chopstick and pushes up against a tape measure. Tape measure releases and launches back up to the body of the tape measure.
I: Tape measure falls hitting toilet paper roll into garbage.
Forms of Energy:
When radio waves and micro waves are given off of the phone, radiant energy is used. Electrical energy is used to produce sound in the speaker. Sound energy is emitted by the speaker. The ball is at an elevated point and therefor has gravitational energy. The ball rolls down the board using mechanical energy. The HotWheels track has a stretched elastic with elastic energy that slingshots the toy car forward. Mechanical, gravitational, and elastic energy are used throughout the rest of the machine.
Radio waves and micro waves are given off by the phone to the speaker (radiation), the speaker uses electricity to produce the sound. The sound vibrates the ball and pushes it off. The ball falls from a height using gravitational energy and then rolls down the board with mechanical energy. The ball hits the button on the car track, and this releases an elastic which uses elastic energy to push the car into mechanical energy. Mechanical energy is continued to be used until it reaches step E, which uses mechanical and gravitational energy interchangeably.
Arithmetic Series are a way to find the sum of a whole group of numbers quickly as long as you have the first and the last number ( & , x being the final term). When you add the first and last number together, you get the sum, and the sum of the rest of the numbers. If you were to add the second number and the second to last number together, you would get the same sum as the first and last! This continues throughout the entire series of numbers.
If you are looking for the sum of all numbers together, you need to do an extra step. You divide the total number of terms by two, and multiply it with the sum of the first and last numbers. When you do this, you get the sum of all the numbers in the entire sequence (or at least the amount of numbers you want from the sequence). This works even if there is an odd number of terms because for example, if it has 19 terms (18 pairs), and 19 divided by 2 is 9.5, the .5 has the missing number inside of it.
This week we started our unit on Sequences. Sequences are how terms change consecutively, whether they go up and down by the same amount (Arithmetic). Multiplying or dividing (Geometric). Or another way (Other Sequences).
This will focus on arithmetic sequences, sequences that go up or down by the same amount.
In a sequence where you are only given one number, you will likely be given , which stands for difference as in the difference between the two numbers. If it is positive, then it goes up as you move to the left and down as you go to the right, and if it’s negative, it’s vice versa.
_,_,_,0,_,_ to -6, -4, -2, 0, 2, 4
If you are looking for a specific term or number in an arithmetic sequence, you can find it rather easily without having to use the rule over and over again until you get to that term.
If you use a specific formula, you can find the number you need without finding the difference over and over again.
We learned more about graphing and linear equation. W learned about different ways to find solutions to equations. They are Inspection, Substitution, and Elimination.
Inspection is only used when a system is very easy and understood. It is basically just eyeballing the question and guessing what the solution is. You can test your solution by plugging the numbers in the appropriate spots (x and y).
Substitution is another method to find solutions, but it uses algebra. You can choose one of the equations, and then choose on of the variables to isolate. Then you plug it into the correct spot on the other equation. You then use algebra to solve the equation, and then use the answer to plug in to find the other variable.
Elimination is used when there are no coefficients of 1. You start by adding the two equations together (you can subtract but it doesn’t work as well). You want to make a zero pair by making either the x or y cancel the other out. If they don’t do this from the start, you can multiply one of the equations or both of them to get one, and then do your adding. Once you have the answer to one variable, you plug it into the equations and find the other.
This week we further continued unit 7/8 by learning about point-slope form and general form. Both of which are put into a different form than slope formula. Point slope form is useful for doing quick algebra, and general form has no fractions and other “imperfections”.
Point-slope form looks like the following:
is the slope. is not connected to a point, but is. The same goes for and . You can take an equation or “hints” to make a point-slope formula.
To further turn this into slope formula and make it easier to understand, you use algebra and steps.
continuing with ex.
General form is the “pretty useless” form, pretty, but useless. It contains no fractions or decimals, but doesn’t tell you about the graph itself. The equation usually looks something like ax ± ny ± b = 0. the x is always first, y is always second, x is always positive, and everything is always on one side equalling zero.
You can change all forms/formulas into general form.
slope formula with fractions.
General form uses no fractions and follows several rules as listed in the paragraph above. It is used to take away fractions and “imperfect” parts of a formula, but it doesn’t tell you anything until it is changed into another form.
We researched several different chemical reactions, but eventually settled on The Black Snake. We looked at the components to make sure it wasn’t dangerous, or at least not too dangerous. The Black Snake uses powdered sugar and sodium bicarbonate (baking soda) along with rubbing alcohol. These chemicals aren’t inherently bad, but alcohol fumes can be dangerous. Another danger is when lighting it on fire to commence the reaction, because fire can obviously be dangerous.
To make The Black Snake, you take 4 parts baking soda, and 1 part powdered sugar, and mix it together. Make a vessel out of preferably tinfoil filled with sand. Make a divot in the sand, and pour the mixture into it. Put rubbing alcohol around the edges of the mixture, and a little bit throughout the middle. Use a barbecue lighter to begin the reaction. A snake made of what looks like ash emerges from the white powder mixture. The snake is very light and airy because of gases produced during the experiment. The snake can grow quite long, but doesn’t always.
What is happening is the sugar C12H22O11 combusts and turns into carbon dioxide and water vapour, this decomposition forms the snake. The baking soda is added to help the experiment rise (2NaHCO3 → Na2CO3 + H2O + CO2), just like how it is used in baking. Reactions:
Sugar combusts into water vapour and carbon dioxide: С12H22O11 + 12O2 → 12CO2 + 11H2O
Decomposition into carbon and water vapour: С12H22O11 → 12C + 11H2O
Baking soda decomposes into carbon dioxide, water vapour, and sodium carbonate: 2NaHCO3 → Na2CO3 + CO2 + H2O
The outcome should be a carbon, black snake. It should be light, look and feel like ash, and should be quite delicate. The snake is not edible, you can touch it but it is not recommended. It can be very hot after burning. Best to do in outdoors or under fume hood because of alcohol fumes produced. The snake and all components of experiment can be thrown out in a household garbage.
The experiment can seem magical because when it is growing, it looks as if it is alive and moving, like a snake. It could also possibly look like a plant growing. It’s like creating life because of its natural seeming movement, even though it is just burning, rising chemicals.
Maric, Vladimir, and Teh Jun Yi. “How to Make a Fire Snake from Sugar & Baking Soda.” WonderHowTo, WonderHowTo, 18 Oct. 2017, food-hacks.wonderhowto.com/how-to/make-fire-snake-from-sugar-baking-soda-0164401/.
“Hooked on Science: ‘Black Snake’ Experiment.” SeMissourian.com, 3 July 2013, www.semissourian.com/story/1983035.html.
This week we continued unit 7 and learned about slopes. A slope is like moving from one “nice point” to another. A nice point being a point on an exact measurement, basically on a vertex of a graph’s square. It gives you a fraction, for example 4/5. The 4 being the vertical distance you need to reach, and the 5 being the distance you need to cross horizontally. A slope is shown with the variable , example: = 3/2. The slope is basically telling you how steep a line is. You know the slope is correct when it always hits a nice point whenever it’s used. It should work on the same line forever.
The steepness is shown in the fraction in the form of rise/run (rise over run). The rise is y, run is x. When the rise is 0/n (0), it is a horizontal line, and n/0 is vertical, and is an “undefined” slope.
Lines can be considered negative or positive. This can be determined just by looking at them. A line facing one way is positive, and if it’s the other, its negative.
Sometimes you are given two coordinates/points, and asked to find the slope between the two. To find this, you must subtract its x’s and y’s. and .