TOPICS
ENGINEERING
Electrical Engineering
Electrical Engineering is the branch of engineering that deals with the invention, creation, improvement, and maintenance of electrical tools, devices, and equipment. Electrical engineering, and engineers who specialize in this area, are crucial in today’s energy and technology-driven world. From X-rays to the lights in our homes to our cell phones, almost everything that runs on electricity has been made possible by electrical engineering.
ELECTRICAL ENGINEERING TOPICS:
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Electricity
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Electricity is a form of energy. Electricity is made of atoms and is the flow of tiny particles in the atom that naked eyes can’t see called electrons and protons. An electron would have a negative charge, while a proton would have a positive charge; these charged particles are always trying to pull each other together. But when two particles with the same charge (like 2 electrons or 2 protons) come into close contact, they will push away from each other. Electricity comes to be when electrons are pushed and pulled from one atom to another.
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Circuit Analysis
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A Circuit Analysis is a process of studying and obtaining all the currents and voltages in a network of connected electrical components. It involves analyzing electrical quantities such as voltage and currents with the use of calculations. The following are basic units of electricity:
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Current: Current refers to the flow of electric charge in a circuit. It is the rate of charge flow past a given point in an electrical circuit.
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Voltage: Measured in volts (V), voltage is the pressure from a circuit’s power source that pushes the charged electrons through a loop.
If you want to learn more about electrical engineering, check out the links below!
https://www.nationalgeographic.org/topics/electricity/?q=&page=1&per_page=25
https://kids.britannica.com/kids/article/electricity/353091#
https://www.youtube.com/watch?v=3nB1Ntku06w
https://www.youtube.com/watch?v=ru032Mfsfig
Newton’s Third Law
Have you ever tried to push a wall with your hands? What did it feel like? Most likely, if you tried to push a wall, you would feel like the wall is somehow pushing you back. This is just one of the many manifestations of Newton’s third law of motion.
Issac Newton, the famous English physicist, and mathematician presented the Third Law of Motion in his book series entitled “Principia Mathematica Philosophiae Naturalis” in 1686. The law is very simple and states that for every action, there is an equal and opposite reaction. This means that there are always two forces that are the same; if object A exerts a force on object B, then object B will also exert an equal amount of force on object A. Newton’s third law of motion can be seen in everyday life all around you. A better example of this would be when you kick a ball with your foot. When your foot (object A) hits the ball (object B), you will feel the impact of your kick on your foot, and the ball will also move in the direction of your swing.
Engineers apply Newton’s third law of motion when designing and constructing rockets and other projectile structures. To get a rocket ship to launch, engineers design the ships to burn fuel downwards so that an opposing upward force will push the rocket into the air.
To learn more about Newton’s third law of motion, check the resources below
https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law
https://www.grc.nasa.gov/www/k-12/airplane/newton3.html
https://www.youtube.com/watch?v=TVAxASr0iUY
https://www.education.com/science-fair/article/newton-law-motion-action-reaction/
https://www.kiwico.com/diy/Science-Projects-for-Kids/3/project/Balloon-Propeller-Newtons-Third-Law-/33
Momentum and Collisions
When objects move, momentum is present. Momentum is the measurement or “power” of mass in motion. In physics, momentum (p) is a product of a moving object’s mass (m) and velocity (v) and can be represented by the equation p = mv. The momentum equation tells us that the bigger the mass of the object and the faster it is moving, the greater the momentum. Let's use a truck and a bike to better understand this concept. If a truck and a bike are moving at the same speed, the truck’s momentum will be much bigger than the bike’s momentum because it is much heavier. Similarly, if two trucks had the same mass but Truck A was faster than Truck A would have more momentum than Truck B. When talking about momentum, the unit of measurement we use is kg m/s.
When two objects bump into each other, we call it a collision. Collisions happen all the time and don’t necessarily mean that there was an accident involved. Some examples of collisions in everyday life would be a ball hitting a bat, your fingers striking your keyboard, or your feet hitting the floor when you walk. When two objects that weigh the same and move at the same speed collide with each other, they will react in opposite directions. For example, if two toy cars with the same weight and the same speed collided with each other, one car will go one way and the other will go the opposite direction. If the objects are moving towards each other but are not the same weight and are not going at the same speed, one object will slow down and lose momentum.
However, the other object will gain momentum and speed up.
To learn more about momentum and collisions, check out the resources below!
https://www.coolkidfacts.com/momentum-collisions/
https://www.bbc.co.uk/bitesize/guides/z9499j6
https://www.youtube.com/watch?v=Y-QOfc2XqOk
https://www.youtube.com/watch?v=0zxTIn67q3Y
https://www.metrofamilymagazine.com/simple-science-experiment-conservation-of-momentum-with-marbles/
https://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Egg-Drop
Kinetic and Potential Energy
Did you know a rolling ball has energy too? It has what physicists call, Kinetic Energy. Kinetic energy (KE) is the energy an object has because of its motion. It can be calculated using the velocity (v) and mass (m) of the object, as seen in the equation KE = 1/2mv2. The standard unit of kinetic energy is the joule (J).
If Kinetic energy is produced by an object’s motion, Potential energy is due to an object’s position or state. Let’s say that you are holding a ball in your hand at an eye level. Because the ball is at a height, it has potential energy but once you let go of the ball and it starts to fall, potential energy is transformed into kinetic energy since it is now in motion.
Let’s use a roller as an example of kinetic and potential energy. As the roller coaster cart ascends higher and higher, the more potential energy it gains. At the top of the tracks, the biggest amount of kinetic energy is produced. As the cart starts to move down the tracks at a fast speed, it gains kinetic energy and loses potential energy.
To learn more about Kinetic and Potential Energy, check the resources below!
https://www.youtube.com/watch?v=quxEz2qxo9s
https://www.youtube.com/watch?v=g7u6pIfUVy4
https://www.mathsisfun.com/physics/energy-potential-kinetic.html
https://www.fi.edu/sparkofscience/potential-and-kinetic-energy
Strength of Materials
If you were to build a bridge to help you cross a stream, what kind of material would you use? Most likely, you would say that you would build your bridge with a strong and sturdy material like wood or steel. In the real world, engineers might ask a similar question: what kind of materials should we use to build bridges for cars to cross with? What kind of materials should we use for a skyscraper? To engineers, the material they use is just as important as the design of a project. Materials, or substances, have many different properties.
The strength of a material, also known as the mechanics of materials, is an important property to consider when building and designing any infrastructure. Strength is the amount of force needed to break the material down and is described in units of pressure. The harder it is to break, the stronger the material is. There are three types of ways to look at a material’s strength: Yield Strength, Ultimate Tensile Strength, and Fatigue Strength.
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Yield Strength
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The amount of stress a material can take without permanent deformation.
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Ultimate Tensile Strength
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The amount of stress a material can take before breaking.
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Fatigue Strength
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The amount of stress a material can take one million times over and over again before breaking.
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To learn more about the strength of materials, check out the resources below!
https://www.teachengineering.org/lessons/view/cub_mechanics_lesson07
https://wiki.kidzsearch.com/wiki/Strength_of_materials
http://www.primaryresources.co.uk/science/pdfs/rsc_tc_nc1.pdf
https://www.generationgenius.com/videolessons/material-properties-and-purposes-video-for-kids/
Stress and Strain
In mechanics, Stress would refer to a force applied per unit area of a material that will cause a change of shape. There are two types of stresses that a material can experience: Tensile Stress and Compressive Stress. When a force is applied and it causes the material to stretch, it is tensile stress. Try imagining a hanging metal pillar with a very heavy weight tied to the bottom; because the weight is pulling the pillar downwards and it stretches, it is experiencing tensile stress. Compressive stress on the other hand squishes the material, in this example, imagine the weight on top of the pillar slowly crushing it.
Strain is the response of a material to stress. It is defined as the change in the length of the material as represented by the formula (Initial Length - New Length) divided by the Initial Length. For a material where compressive stress has been applied, the length of the material will most likely decrease.
Engineers take note of a material's stress and strain in order to analyze structures and figure out how to use and design certain materials in order to ensure that it is safe.
To learn more about stress and strain, check out the resources below!
https://www.pbs.org/video/reaching-breaking-point-materials-stresses-and-toughness-c8behr/
Simple Mechanics
Today, machines are all around us! Things like robots or cell phones might come to mind when we think of the word ‘machine’, but even before computers came to be, humans have been using simple machines to get things done easier and faster. A simple machine is a device that makes work easier by helping us humans change the strength or direction of a force. There are 6 basic types of simple machines: Lever, Wheel and Axle, Pulley, Inclined Plane, Wedge, and Screw.
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Lever
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A lever is a bar or board that sits on a fulcrum. A lever can transfer and increase the force applied to one side of it, which is why it can help lift heavy things. An example of a simple machine that uses a lever is a see-saw! On your own, you might not be able to carry your friend who might be the same weight as you, but on a see-saw, you would more easily be able to lift them into the air (and have some fun at the same time!).
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Wheel and Axle
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The wheel and axle is a simple machine that uses a wheel with a rod attached in the middle to help lift loads or move objects. An example of a wheel and axle are the wheels on your bike. This simple machine helps you move faster with less force!
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Pulley
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A pulley is a wheel with a rope attached to its edge. The pulley helps change the direction of the applied force from one end of the rope to another. An example of a pulley at work might be a flagpole.
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Inclined Plane
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An inclined plane might be the simplest simple machine of all! It is a flat surface wherein one end is higher than the other. It helps heavy objects slide up to a higher point. An example of an inclined plane would be a ramp.
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Wedge
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A wedge would be two inclined planes put together back to back. It would have one edge that is thinner than the other and it is usually used to push objects apart. Examples of a wedge would be a knife or ax for cutting or chopping.
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Screw
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The screw is a special inclined plane that is wrapped around a cylinder or pole. Screws can either lift things or hold things together. Items such as jars, lids, and (of course) screws are examples of screws!
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When you put together multiple simple machines into one machine, you will now be creating a compound machine.
To learn more about simple machines, check out the references below!
https://www.pbslearningmedia.org/resource/idptv11.sci.phys.maf.d4ksim/simple-machines/
https://www.ducksters.com/science/simple_machines.php
https://kids.britannica.com/kids/article/machine/400129