Hot Education How-Tos

How To: Find a slope of a straight line with: Ax + By + C = 0

In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ...

How To: Graph a line using an x-y table

In this video the instructor shows how to graph a line using X-Y table values. He specifies a four step approach. In the first step he picks numbers for the value of x. In the next step he substitutes the values of x in the equation of the line to obtain the corresponding y values, in the third step he plots these ordered pairs on a graph sheet. Finally in the fourth step he joins them resulting in a straight line for the given equation. This video clearly shows how to graph a line using an X...

How To: Find a slope of a line parallel/perpendicular to it

This video tells you how to find a slope of a parallel / perpendicular to it. In the equation y = mx + c, m is the slope. To calculate the slope of a line that is parallel to another line, you have to consider the rule m1 = m2 which means slope of the first line m1 is equal to the second line m2, if both the lines are parallel. Take the equation y = 2/3x - 7.2/3 is the slope. According to the rule m1 = 2/3 and so m2 = 2/3.Now to calculate the slope of perpendicular line you have another rule ...

How To: Make aluminum nitrate nonahydrate

Aluminum nitrate nonahydrate is a crystalline hydrate - a salt of aluminum and nitric acid - Al(NO3)3·9H2O. It's used for a variety of things such as antiperspirants, corrosion inhibitors, and petroleum refining, or… glow-in-the-dark powder. Watch this science video tutorial from Nurd Rage on how to make aluminum nitrate nonahydrate with Dr. Lithium.

How To: Construct a vinegar battery and power a calculator

Using only vinegar and a few simple materials, it is possible to construct a working battery. This science video tutorial explains how to construct and use a battery like this to power a calculator. A good science project as part of an introductory electricity course. This project can be used as a science fair project or merely for fun. If you've ever wanted to make your own battery, know is the time, this science experiment will show you how.

How To: Dissect a frog and look at its anatomy

This video tutorial will show you the steps on how to dissect a frog. First, you'll have to get a frog, then you'll have to make sure it's dead, then perhaps wash it off. Then just take a look at the external anatomy of the amphibian before slicing it open. To slice, you'll need dissection forceps or tweezers and the dissection scissors. From then on, you'll be knee deep in frog anatomy. Tons of internal organs for you to learn from. So, watch this science video for learning about the anatomy...

How To: Tie off a suspension ring for rope bondage

If you're planning on doing some bondage knots, you better learn how to do it right. This video shows you how to properly tie off a titanium suspension ring for use in your bondage activities. This video is clear and straight forward, using a large piece of rope, making it easy to see exactly how it's done. Remember to be careful with your S&M knots, especially if you're suspending someone's weight.

How To: Observe the Full Moons in 2011 (Lunar Calendar)

When's the next full moon? Every time I've looked at the moon, I've wondered if it was full. Sometimes it looked like it was, but it's really hard to tell for sure unless you know the exact date of the full moon. Seriously, there's at a couple days before and after the full moon that could easily pass as full. At least, to someone like me who isn't naturally in tune with the moon's cycle (and doesn't have perfect vision).

How to Be Your Own SpaceX: Design, Build & Test Liquid-Fueled Rocket Engines

Move over NASA— SpaceX is taking over. Well, not really. But today, the privately funded spacecraft company broke all expectations when their Dragon capsule fell to a soft landing in the Pacific Ocean, completing an undoubtedly successful demo flight of nearly two full trips around Earth. It was the first re-entry of a commercial spacecraft ever, bringing commercial space transportation closer to reality.

How To: Find the volume of a swimming pool

In this video, we learn how to find the volume of a swimming pool. To do this, you will first need to find the measurements of all the sides that are on the pool. After this, you will plug in the measurements that you found into the equation to find the volume. This equation is: V=AH, volume= area(height). So, plug in the area and the height to the equation for A and H and then multiply these two together. Once you do this, you will find the answer! Don't forget to label the units on the fina...

How To: Use a unit circle to find trig values

In this tutorial, we learn how to use a unit circle to find trig values. The unit circle has a radius one, use the definition of the trig functions to figure this out. Write them down if you need to, to remember what they are. You will also need two special triangles to help figure this out. Make sure you know the short side is opposite 30 degrees. Now, draw out your graph and find the ordered pair of pie, then find the y value of it. From here, find the cosine, tangent, and other units using...

How To: Shrink plastic with household materials

In this video, we learn how to shrink plastic with household materials. You will need: tin foil, plastic container, scissors, glove, and colored markers. To start, you will preheat the oven to 325 degrees. Then, cut a piece of the plastic out in a square shape. Next, draw whatever you want onto your piece of plastic. Make it as colorful as you would like to! When finished, put this in the oven using a glove. Make sure it's on the foil when you put it in. Then, leave it in for less than a minu...

How To: Build a catapult out of rubber bands & a wire hanger

In this tutorial, we learn how to build a catapult out of rubber bands & a wire hanger. To do this, you will first need: one wire hanger, plastic spoon, rubber bands, small marshmallows, and measuring tape. Now, hold your hand in the center of the hanger and pull up both sides around it. After this, fold back the front for balance and straighten it up so it's stable. Next, you will take one rubber band and put it around the sides. Then, take the spoon and put it in between the rubber band and...

How To: Make polymer putty with household materials

In this tutorial, we learn how to make polymer putty with household materials. You will need: borax, white glue, water, 3 plastic cups and spoons, and food coloring to color your putty. Now, dissolve 4 tbsp of Borax in 2 liters of warm water. Then, prepare equal parts of glue and water together. To make this, you will need 2 parts of the glue solution to 1 part of the Borax solution. Once you mix these together, you can add in some food coloring to it. Pour this into different cups to make di...

How To: Make iron sulfide with sulfur and iron

In this home-science how-to from Household Hacker, we learn how to create an exothermic reaction by combining sulfur with iron, producing iron sulfide in the process. For all of the details, including step-by-step instructions, as well as to see what happens when these two elements meet, watch this video guide.

How To: Properly balance chemical equations

In this video, we learn how to properly balance chemical equations. You will see what substances are in each side of the equation. You will then need to count the atoms that are on each side of the chemical equation. Once you write down the number of atoms on each side, you will need to even them out. To do this, you need to change the coefficients within the equation. These change the total number of atoms inside of a chemical. Once you do this, you will add more to each atom present and the...

How To: Balance chemical equations the right way

In this tutorial, we learn how to balance chemical equations. The first thing you want to do is to draw a graph and label one side reactants and the other side products. Go through each of the atoms that are in your equation on both sides. Write out how many atoms are in each chemical. Then, find a common multiple that will give you and equal amount on each side of the equation. Continue to do this same for all the chemicals in your equation, then when you are finished write it out. Now you w...

How To: Graph & shade a polygon of constraints

This video shows us how to graph & shade a polygon of constraints. Start out by finding the non zero constraints and the other constraints and inequalities. You will need to know how to graph before you begin to do this equation. Look at the first constraint and then fill in the X and Y sign in your table. Continue on to do this for the other two constraints that you have. Once you have these written down and in front of you, it's just a matter of graphing. Start to graph with the given coord...

How To: Change fractions to decimals

In this tutorial, we learn how to change fractions to decimals. Once you learn how to do this, it can help you learn more levels of math. Start out with easy problems and work your way up to more difficult ones. First, try rewriting the equation. Take your top numerator and divide it out by hand by your denominator. After you have done the long math for this, the number that is on the top of the division sign will be your answer. You will need to have a good sense of what numbers add into wha...

How To: Synthesize copper(II) carbonate & sodium bicarbonate

This actions is a video tutorial in the Education category where you are going to learn how to synthesize copper(II) carbonate & sodium bicarbonate. For this you will need copper sulphate which is available in root kill and sodium bicarb which is baking soda. Take 100g of copper sulphate and dissolve in about 400ml of water. Now take 69.27g of baking soda. Add baking soda very slowly and keep stirring the solution. You got to be very careful as the chemical reaction will produce lot of carbon...

How To: Draw an isosceles trapezoid

This is a video tutorial in the Education category where you are going to learn how to draw an isosceles trapezoid. This video demonstrates how to draw an isosceles trapezoid with a long base (B), a short base (b) and a 35 degree angle. First you draw the long base. Now center the short base at the center point of the long base and mark the end points of the short base with dots. Next draw perpendicular dotted lines from the dots extending upwards. Draw 35 degree angles from either end of the...

How To: Use the PRIME operator in math

In this video, we learn how to use the PRIME operator in math. The prime operator is the opposite of something in the equation. Take a look at the illustration in the video that is shown. Once you see that, you will be able to tell what A prime and B prime are. A prime is the opposite of "A". If a number is shaded in "A" it should not be shaded in "A Prime". The same goes for the prime of the letter "B". Just pay attention to what the numbers selected for each letter is, then use the opposite...