Active Education Posts

How To: Demonstrate Newton's law of inertia

This short video clip shows seven demonstrations of Isaac Newton’s first law of motion– the law of inertia. Newton’s law of inertia states that objects moving at constant velocity will continue moving at constant velocity, unless acted upon by an outside unbalanced force. Six of these demonstrations (excluding number six) are from Tik Liem’s book Invitations to Science Inquiry.

How To: Translate a sentence into math symbols

We will be translating the sentence "twice y differs from 5 by more than two, “into a mathematical equation. The word twice generally means two times, so 2*y (because y comes next in the sentence). Differs normally means is different and a difference from something in a mathematical sentence means subtraction most of the time, thus minus five. We don't know if we’re talking about below 5 or above 5 on the number line, so we put absolute value around the equation. More than implies a greater t...

How To: Use ">" (greater than) and "<" (less than) symbols

In this video the author explains how to identify the less than (<) and greater than (>) symbols and when to use them. She explains to us to relate the numbers to animals stating that the smaller numbers are smaller animals and bigger numbers are bigger animals. Now she tells us to imagine that smaller animals are eaten up by the larger animals. So she shows a smaller number comes on the left side of '<' sign and bigger number comes on the right side of '<' sign stating that the bigger number...

How To: Evaluate a line integral along a straight line segment

This video tutorial is in the Education category which will show you how to evaluate a line integral along a straight line segment using the definition of the line integral. This video evaluates a line integral along a straight line segment using a parametric representation of the curve (using a vector representation of the line segment) and then integrating. A vector representation of a line that starts at r0 and ends at r1 is r(t) = (1-t)r0 + tr1 where t is greater than equal to 0 and lesse...

How To: Understand fractions with patterns

This is an educational site where we can learn about math lessons with example videos, interactive practice problems and can do self-test. The associate teacher in the video teaches us about fraction problems. She has written four numbers on the board, which is 1 1/4, 1 1/2, 1 3/4, and 2. She explains how to find the next three numbers following the same pattern. The teacher in the video tells that the key in solving the problem is to think of 1 1/2 as 1 2/4. Each number in the given problem ...

How To: Solve for the missing ratios or proportions

In this video the tutor shows how to solve the missing ratios or proportions. He explains it with an example, where a number in one of the ratios is missing and he intends to find this value. He shows the example of cross multiplication, where you multiply the values on the either side of the equation diagonally and finally solves the equation which results in the value of the unknown value. This is an introductory video explaining how to use rations and proportions to find missing values.

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: Form hydrothermal quartz

How can hot water form beautiful quartz crystals? This mine is red Georgia clay, with veins of minerals running through it. The veins are hydrothermal. Hydro means water. Thermal means heat. So the veins were caused by hot water. But how could hot water form quartz crystals?

How To: Write a great essay for the SAT test

In this four part video tutorial series, learn how to write a 12 score essay for the SAT test in just ten days. The SAT essay is designed to measure your abilitity to develop a point of view on an issue presented in an excerpt, support your point of view using reasoning and examples from your reading, studies, experience, or observations, and your ability to follow the conventions of standard written English. Follow these steps presented in this video, and score at least a 10 on your SAT essay!

How To: Revive a drowned fly

Ever wished you were Jesus? This how-to video can bestow you with life-reviving powers. It's not a trick. See how you can revive a seemingly drowned fly with salt by watching this educational and instructional video. Let the resurrection begin.

How To: Calculate percent error in chemistry lab activities

If you want to know how to calculate percent error easily, you should watch this video. Error is the amount of deviation from accurate values. Error calculation is not possible, unless you make a quantitative measurement of the various quantities involved in your experiment. Measurement can help us in calculating errors and knowing how right we are in our theoretical models. In calculating percent error, We need to get the experimental value and the value which you are aiming at, which is the...

How To: Convert numbers in and out of standard form

In this video, we learn how to convert numbers in and out of standard form. Standard form is a useful way of writing down very large numbers and very small numbers. To do this, you will look at the number you have and ignore the zeros that are just at the end. Then, write down the basic numbers. Put a decimal point in this number to make it between one and ten. Now, write down x 10 and put the power for how many places the decimal point moved to get to the new number. This will help you write...

How To: Calculate the age of the universe w/ Hubble's constant

This is a great instructional video on how to calculate the age of Universe from Hubble's constant. The speed the galaxy moves away from us is directly proportional to the distance from us. Now think of big bang theory. Hubble's constant is equal to velocity over distance. 1 over Hubble's constant is equal to distance over velocity that is equal to time. Time equals to 1over 71. If you change it into all the same units words it is one over 71000 or 3.09x 10 to the power of 22. It is 3.09x10 t...

How To: Use radiation detection equipment

In this tutorial, we learn how to use radiation detection equipment. To use the dosimeter, you will remove the cap, then place the pipe on and push down on it. A light will come on, and you can use the knob to zero it. When you look in, you will be able to see it's measured in Roentgens per hour. When you are done using this, zero it again. Next, you will have a CD Geiger counter which has three positions for the knob. Whatever it is set on, you multiply the reading by that number. If you tur...

News: World's Simplest Electric Train

The trick in the video is that the magnets are made of a conducting material and they connect the battery terminals to the copper wire, so the battery, magnets and copper wire make a circuit that generates a magnet field just in the vicinity of the battery. The geometry means the two magnets are automatically at the ends of the generated magnetic field, where the field is divergent, so a force is exerted on the magnets.

How To: Build a robot that scribbles on paper

This video explains how to build a robot with the basic ability to scribble on paper. The narrator gives website addresses for more examples on completed robots and various information on the subject. The Robot is built using a plastic cups and wooden sticks for legs and support. A motor is then attached to a wooden stick which is then attached to the top of the plastic cup. One nine volt battery is needed to power the motor. Once the battery has been attached to the motor you must attach the...

How To: Focus your laser to make it burn

In this video, we learn how to focus your laser to make it burn. The best spot for a laser to burn things is at its focal point. This is where the beam from the laser is at its smallest. If you hold a match in front of the beam, it will light it on fire as soon as it's in front of it. If you put two lasers next to each other going the same direction, it won't be able to burn because the light beam is too large. If you position the lasers so the light is smaller, then they can catch something ...

How To: Find percent by mass & percent composition

In chemistry you come across problems which ask you to find the percent by mass and percent composition of each element in a chemical compound. To do this the first step is to compute the molar mass. Use the periodic table to look up the mass of individual atoms and multiply it by the number of atoms to find the mass of that element. Now add up all the masses to arrive at the molar mass of the compound. Now to find the percent composition of an element divide the total mass of each element by...

How To: Calculate the area of a parallelogram

Calculating The Area Of A Parallelogram A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is:

How To: Use the distance formula for two points

In this tutorial, we learn how to use the distance formula for two points. The distance formula is D= the square root of (X2-X1) squared, plus (Y2 minus Y1) squared. It may look confusing, but it's just a derivation of a theorem. First, find the two points that you have and graph them. If you want to know the distance between them, you cannot just count squares if it's a diagonal line. If you remember geometry, you can draw a right triangle over the line to figure out the distance. After this...

How To: Build a magnetic stirring device

In this video, we learn how to build a magnetic stirring device. First you will need: a block of 1 inch thick Styrofoam, a piece of cardboard, 2 magnets, a small electric motor, a piece of non-magnetic metal, a hot glue gun, and a soldering iron. First, draw the shape of your cardboard square on the foam and cut it out. After this, take your soldering iron and melt away the Styrofoam from the outside. Then, make a hole in the middle for where the motor will be placed and push it inside. After...

How To: Make Your Own Homemade Glow Sticks

Glow sticks, a popular favor at parties and outdoor events, and a must-have on Halloween, can be traced back to the United States Navy in the mid-1960s. The military desired improved visibility during night operations, and glow sticks, with their small-size portability and lack of batteries, were a perfect tactical solution.

How To: Streak an Agar Plate

Check out this video tutorial on how to streak an agar plate. What's an agar plate? Well, an agar plate is a sterile Petri dish that contains a growth medium (typically agar plus nutrients) used to culture microorganisms. Selective growth compounds may also be added to the media, such as antibiotics.

How To: Find the area of irregular shapes

This video explains how to find the area of irregular shapes. Draw the shape on a grid or graph paper. This will help you divide your shape into pieces. Draw dotted lines to divide the shape into squares, rectangles or triangles. For instance, if you have an "L" shape, you can divide the shape into two rectangles. Be sure your shapes do not overlap. Calculate the area of each individual shape. The graph paper will help you determine the length and width of each shape. Add the resulting areas ...