Excretory system
The excretory system removes waste and toxins from the human body.
Your skin eliminates waste by sweating.
Your lungs eliminate carbon dioxide.
Your kidneys filter over 180 liters of blood in order to produce urine.
The kidneys filter waste like urea. This liquid that is collected is called urine.
Your kidneys are made up of millions of filtering units called nephrons.

The Law of Conversation of Mass states that the mass of the reactants must equal the mass of the products in all chemical reactions.
I use a simple demonstration to show this point. I use baking soda and vinegar which is a simple chemical reaction, to demonstrate the law of conservation.
Correction:
0:41 I accidentally said grams instead of ounces while weighing the materials. My mistake.

Selective breeding (also called artificial selection) is when humans use animal breeding and plant breeding to develop offspring with traits they desire.
Selected breeding has been practiced for years with plants and animals.
Selective breeding has been used with horses, dogs, rice, wheat and corn

Let’s look at some examples,
Look at these two dogs
This Chihuahua mix and Great Dane shows the wide range of dog breed sizes created using selective breeding

How clastic rocks form. Sedimentary rocks are derived from igneous, sedimentary and metamorphic rocks.
Sedimentary rocks make up around 75 percent of the rocks at the earth's surface
Let’s take a look at how clastic sedimentary rocks form. Clastic sedimentary rocks are the group of rocks most people think of when they think of sedimentary rocks. Clastic sedimentary rocks are made up of pieces of pre-existing rocks called clasts.
These sedimentary rocks follow wedcc in order to form
Weathering:
Erosion
Deposition
Compaction
Cementation

Air masses are large bodies of air with similar temperature and humidity throughout.
In the video, I cover maritime and continental air masses. Maritime air masses form over the water and continental air masses form over land.
In addition, there are maritime tropical, maritime equatorial, maritime polar along with several types of continental air masses.

Ocean Biome Characteristics
The earth is 70% water. 97% of this water is made up of our oceans and seas.

Most of us only experience the ocean from the beach or on shore. If you go underwater and out into the ocean you discover it is teaming with life.

The ocean can be divided into 5 major oceans
The Pacific which is the largest, the Atlantic, Indian, southern, and the Arctic ocean.

The ocean is teeming with life. It includes animals as large as a 40-foot humpback whale and as small as microscopic plankton.
It includes a huge variety of plants and coral reefs that stretch for miles.
It also includes the largest mountain range called the mid ocean ridge.
The ocean impacts our weather and has been used for thousands of years as trade routes.

We play on the beaches of oceans and wonder what can be found in the Mariana trench which is 32,000 feet deep.

So there you have a very quick overview of our most diverse and largest biome-the ocean

Friction is the force that opposes motion between any surfaces that are in contact. There are at least four types of friction: static, sliding, rolling, and fluid friction. Static, sliding and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases

Static friction occurs when an object is resting on a surface. The static friction between the boots and the snow allows this person to stand and shovel snow.
When you rub your hands together you experience sliding friction.
When you ride a bike you depend on the rolling friction of the tires.
Sky diving depends on fluid friction between the air and the parachute to slow down.

In this video, I cover many real-life examples of friction and how friction helps you in everyday life.

Newton's third law of motion is all around us. In this video, I show real-world examples of the 3rd law of motion.
Why is Newton's third law of motion important?
For every action, there is an equal and opposite reaction.
For example, when you skateboard and push backward, the opposite reaction is to drive the skateboard forward.
A jet moves forward when the exhaust moves backward. Another example of an opposite reaction to a force.
Other examples include paddling a boat, jellyfish, basketball, and a trampoline.
By watching these examples it will give you a better understanding of how motion works.

What makes a trapezoid a trapezoid? A trapezoid has two parallel sides and two nonparallel sides.
A trapezoid is a quadrilateral because it has four sides.
I also cover,
How to find the area of a trapezoid
The median
How to identify a trapezoid
The shape of a trapezoid
Number of sides
Is a trapezoid a parallelogram?

Use the formula is over of in order to solve 90 is what percent of 360.
The is over of formula has three variables and works to solve many percentage problems such as,
40 is what percent of 80
20 is what percent of 100
8 is what percent 32?

Digestion begins in the oral cavity which we normally call the mouth. The mouth is responsible for mechanical and chemical digestion and prepares the food for digestion. I explain the role of the mouth in digesting food. The mouth has a very important function in digesting food..
The mouth has 32 teeth that help with mechanical digestion and amylase that helps with chemical digestion.

Learn how to calculate force and distance using the work formula.
You can use the work triangle in order to help you calculate either force in Newtons or distance in various units.

0:00 Introduction to the calculate work triangle
0:24 During a race a runner puts out 6000 Joules of work. If he runs a distance of 30 m, how much force did the runner put out?

01:17 John’s output of work was 16 Joules. He pushed the sled with a force of 8 Newtons. How far did he push the sled?

02:05 If it takes 500 Joules of work to move a chair 20 m, what force was needed?

03:01 What distance was your bike moved by a force of 20 N if the work was 1600 Joules?

Learn how to use a factor tree in order to find the lowest common multiple.
I find the LCM of 12 and 15.