How do you build a circuit?

A basic component of electrical engineering is a circuit. A circuit is simply a loop that has a current running through it. The current helps the circuit do whatever it was designed to do, like send information from one source to another or power an object, like a LED light. So, how do you build a circuit?

It's actually pretty simple. All you need is a power source and connections. See, most power sources, like a battery, have two terminals: a positive one and a negative one. Current is created when there is a path from one terminal to the other. This path can be created using wires. Whatever is put in the circuit will also get the current, helping it do whatever it needs to do.

Most of the times, engineers like to test out their circuits before they finish them. This is when a breadboard is used. The breadboard has holes on the top so that you can use wires to connect the things in your circuit together. Each column of the breadboard has a wire underneath it to make checking your circuit easier. You make your circuit on the breadboard and check to see if it works right! 

Once you're sure your circuit does what you want it to, you finish it by fixing it to a circuit board. A circuit board is made out of copper and is printed with your wire connections on it. You can design it so that it works for your circuit. Once you get your circuit board, you just need to attach your elements to it, and you have a fully finished circuit, like the one below!

These days, there are new inventions to make this process simpler. One cool new thing is the Circuit Scribe. It has ink that has the same qualities as wires do, so the ink can carry current through them. Now, we can just use paper to make our circuits on instead of breadboard and circuit boards. Check out www.kickstarter.com/projects/electroninks/circuit-scribe-draw-circuits-instantly to learn more!

Bake the perfect cookie!

Have a bake sale coming up? Or maybe a sweet tooth that won't quit? Then we have got the experiment for you!

Make your own Rubber Band car!

How can you make a car with just things around your house? Read on to find out!

The Experiment

Materials:

• 2 paper or plastic cups with lids
• Scissors
• Duct tape
• Stick
• 3-4 rubber bands
• 1 paperclip
• beads with big holes
• Pen or pencil

Try it out:

1. Cut out a small hole on the bottom of each cup. Make sure that the holes line up when you put the bottoms of both cups together.
2. Tape the bottom of both cups together.
3. Poke holes in the center of the lids of both cups. 
4. Connect the rubber bands together by looping them into each other, making a chain. You can do this by putting one rubber band half way through the other, and tucking one end through the center, like this: 
   
5. Thread the rubber band chain through the one lid, the hole in the bottom of the cups and the other lid.
6. Loop a paper clip through one end of the rubber band chain to stop it from going into the cup. 
7. On the other end, put a bead in the rubber band, and then put the stick through the remaining end of the rubber band loop. Your finished car should look something like this:
   
8. Twist up the rubber band and let the car go! 

What's happening

When the rubber band is twisted, it is storing potential energy. Potential energy is energy that is stored in an object. When the rubber band is released, this energy gets turned into mechanical energy. Mechanical energy is energy that does work. 

The only place this energy can be let out is in the paper cups, causing the paper cups to turn, making your car move forward. 

If you thought this was cool...

This project is related to mechanical engineering. You can find out more here. Some concepts used in this project are potential and mechanical energy. You can find out more about energy through this project.

Make your own Marble Run!

Can you get a marble to drop into a cup from the other side of the room? Try out this experiment and find out!

Tackling Friction

Friction is a force that helps things slow down when they're moving. Friction is what makes your brakes work on your bike or car, and what helps a ball roll on the ground. But what happens when you want to have less friction? Try out this experiment and see if you can figure it out!

The Experiment

This experiment is based on a similar experiment by education.com.

Materials:

shoebox
balloon
scissors
straws
tape
ruler

Try it out:

1. Ask an adult to help you cut a small hole on one side of the box. This is where the end of the balloon will stick out.
2. Put the balloon through the hole so that the large part of the balloon is inside the box and the end is sticking out.
3. Blow up the balloon, then hold the end closed with your fingers. Put the box on a flat surface, like the floor, and use tape to mark the starting point.
4. Let go and measure how far the box travels. Try this a couple of times.
5. Now cover the floor with straws like this. You'll need at least 3 feet of straws:

    6. Place the box and balloon on the straws and see how far they go this time.

    7. Finally, glue or tape two straws to the bottom of the box like a sled

   8. Place the box and balloon back on the floor and see how far they go.

Which box went the farthest? Why do you think that is?

What's happening

Friction is a force that acts in the opposite direction as the direction something is moving. When the box moves forward, friction pulls it back. The stronger the friction is, the less the box can move.

What makes friction stronger? There are a couple of different things. One is how rough the surface is. A rough surface like carpet or the street will have more friction than a smooth surface like a wood floor. When you pushed the box on the lined up straws, the straws roll around and have very little friction because they are very smooth.

Another is the surface area of the object that is touching the floor. If the surface area of the object is bigger, that means the friction can push on a big area, which makes the friction stronger. When you glued the two straws on the bottom of the box, you gave the friction less surface area to push on. That makes the friction weaker so the box can move farther.

If you thought this was cool...

This experiment is related to mechanical engineering. You can find out more here.
Some ideas from physics in this experiment include forces and friction.

Q&A: What is nanotechnology?

Do you think there is nanotechnology in your every day life? What is nanotechnology anyway? Read this post and find out!

What is nanotechnology?

When you measure things, you use different scales. For example, you measure the height of a building in feet or meters, and the length of your finger in inches or centimeters. How would you measure something that's 40 times smaller than the width of your hair? That's when you'd use a unit called nanometers.

Want to learn how to code?

Computer science is all about coding. You type some stuff up in a specific way, and then watch your computer follow your instructions and make magic! Coding is a little hard to teach on a blog post, so here are some cool links you can check out to learn how to code.



http://www.codecademy.com/
http://code.org/

and especially for you young ladies,
http://girlswhocode.com/

If you thought this was cool...

This experiment is related to computer science and engineering. You can find out more here.

Toothpick towers

How tall can you build a tower out of just toothpicks and marshmallows? Try out some of these ideas and see how far you can go!