Rotary cannon
This tool has many barrels. The barrels spin in a circle. This helps them stay cool. It also helps them work fast. They are on big ships and planes. Do you like big machines?
Early Reader · Change the reading level on the articleTechnology articles — Page 69
Explore inventions, engineering, computing and the tools people build to solve problems. Choose an article below; its reading controls let you move between the available levels.
4,107 public articles · Page 69 of 86
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Rotary switch
A rotary switch turns in a circle. It helps move power to different parts. It can work like a fan with speeds. This helps our tools work well. It is a neat little tool. Can you find a switch that turns?
Early Reader · Change the reading level on the articleRotorcraft
Some planes have spinning wings. These wings spin fast. They help the plane go up. Some can land in small spots. This is very cool! Can you see them spin?
Early Reader · Change the reading level on the articleRotterdam Metro
Trains run under the ground in a city. They help many people get to work. The trains move fast on tracks. They can go through long tunnels. This helps us travel easily. Do you like riding fast trains?
Early Reader · Change the reading level on the articleRouting
Computers send messages to each other. They must find the best way to go. This is like finding a path. It helps your data get home fast. It works even if a path breaks. Do you like to find paths?
Early Reader · Change the reading level on the articleRoy O. Disney
Roy helped start a big company. He worked with his brother Walt. They made many fun things. He helped build a large park. It is a special place for us. Do you like big parks?
Early Reader · Change the reading level on the articleR (programming language)
R is a way to talk to computers. It helps us look at lots of facts. It can make pretty pictures too. This helps people learn new things. It is free for everyone to use. Do you like looking at pictures?
Early Reader · Change the reading level on the articleRSA cryptosystem
Computers use a secret code. This code keeps things safe. It uses math to hide words. It helps you send notes. It is very smart. Do you like secrets?
Early Reader · Change the reading level on the articleRTHK
RTHK makes shows for people. They use radio and TV. You can hear music on the radio. You can watch shows on the TV. These shows help us learn. Do you like to watch TV?
Early Reader · Change the reading level on the articleRT (TV network)
RT is a news show. It comes from Russia. It tells stories to many people. It uses many different languages. Some places do not let people watch it. Do you watch the news?
Early Reader · Change the reading level on the articleRubber band
A rubber band is a loop. It can stretch out. It helps hold things together. You can use them for many jobs. They are very helpful! Do you have any at home?
Early Reader · Change the reading level on the articleRuby laser
A ruby laser makes red light. It uses a pink stone. The light comes in quick flashes. This light can help make art. It can even help doctors. Do you like the color red?
Early Reader · Change the reading level on the articleRuby (programming language)
Ruby is a way to talk to computers. It helps people write code. A man named Matz made it. He wanted it to be fun to use. It helps us make things. Do you like to use computers?
Early Reader · Change the reading level on the articleRudder
A rudder helps a boat turn. It is a flat part at the back. It pushes against the water. This makes the boat go a new way. It helps us sail in a line. Do you like boats?
Early Reader · Change the reading level on the articleRudolf Augstein
Rudolf Augstein was a writer. He started a big magazine. He wrote many true stories. He helped people learn the truth. His work helped keep us free. Do you like to read stories?
Early Reader · Change the reading level on the articleRunway
A runway is a long path. Planes use it to fly. It can be made of grass or hard stone. It helps planes take off. It also helps planes land safely. Do you like to fly in planes?
Early Reader · Change the reading level on the articleRussell Simmons
Russell Simmons works with music. He helped make hip hop music. He also made clothes for people to wear. He helped many groups of people. Some people said he did bad things. He said he did not do them. Do you like music?
Early Reader · Change the reading level on the articleRussia-1
This is a TV station. It is in Russia. It shows many shows. Some shows are for kids. It shows news too. Many people watch it. Do you watch TV?
Early Reader · Change the reading level on the articleRussian Railways
Big trains run on tracks in Russia. These trains carry people and things. They go to many far places. The trains help people move around. It is a very big job. Do you like to ride on trains?
Early Reader · Change the reading level on the articleRuth Handler
Ruth was a smart woman. She made a famous doll. The doll is named Barbie. Barbie can wear many clothes. This doll helps kids play. Do you like to play with dolls?
Early Reader · Change the reading level on the articleRyanair
Ryanair is a big airline. It has many planes. It flies to many places. It helps people travel for less money. It is very large in Europe. Do you like to fly in planes?
Early Reader · Change the reading level on the articleRyszard Kapuściński
Ryszard was a writer. He went to many far places. He wrote books about the world. His stories help us learn. He was a very brave man. Do you like to read stories?
Early Reader · Change the reading level on the articleSabiha Gökçen
Sabiha Gökçen was a pilot. She flew planes in the sky. She was the first woman to do this in war. This helped many people know her name. She was very brave. Do you like planes?
Early Reader · Change the reading level on the articleSabot (firearms)
A sabot is a special tool. It helps a small part fly fast. It fits inside a big tube. The tool falls away after it shoots. This helps the small part go far. Do you want to see it fly?
Early Reader · Change the reading level on the articleSabre
A sabre is a curved sword. It has a bent blade. Soldiers used it on horses. It was a very strong tool. People still use it in sports today. Do you like old things?
Early Reader · Change the reading level on the articleSafari (web browser)
Safari is a tool for the web. It helps you see pages on a screen. It works on many Apple tools. You can use it on an iPhone. It is very fast. Do you like to look at things online?
Early Reader · Change the reading level on the articleSafe
A safe is a strong box. It keeps your things safe. It can stop fire or thieves. It might have a lock. It can hide in a wall. Do you have a special box for your things?
Early Reader · Change the reading level on the articleSafety data sheet
A safety sheet is a list of facts. It tells us how to stay safe. It shows how to use things well. This helps people at work. It is a very helpful tool. Do you like to learn new things?
Early Reader · Change the reading level on the articleSafety glass
Some glass is made to be safe. It does not break into sharp bits. It stays in one piece. This helps keep us from getting hurt. It is in many windows. Do you see safe glass?
Early Reader · Change the reading level on the articleSafety razor
A razor cuts hair. It has a guard. The guard keeps skin safe. It helps you shave at home. It is very handy. Do you use a razor?
Early Reader · Change the reading level on the articleSailboat
A sailboat moves on the water. It uses big sails. The wind pushes the sails. This makes the boat go. It is a fun way to travel. Do you like the wind?
Early Reader · Change the reading level on the articleSaint Petersburg Metro
Trains run under the ground here. They go very deep. The stations look like art. People use them to travel. It is a beautiful place. Do you like train rides?
Early Reader · Change the reading level on the articleSai (weapon)
The sai is a metal tool. It has a long point. It also has two small sides. People use it in martial arts. It helps them block or strike. Can you see the sharp parts?
Early Reader · Change the reading level on the articleSakichi Toyoda
Sakichi Toyoda was a great maker. He lived in Japan long ago. He made machines that weave cloth. These machines stop if they have a problem. This helped people make things well. Do you like to build things?
Early Reader · Change the reading level on the articleSalt mining
People dig for salt deep in the ground. It is found in big rocks. This salt helps us live. We use it in our food. It is a very old job. Can you find salt in your kitchen?
Early Reader · Change the reading level on the articleSampling (signal processing)
Machines can catch sounds. They take many small bits. These bits make a sound wave. This helps us save music. It is like taking many quick pictures. Do you like to listen to music?
Early Reader · Change the reading level on the articleSamsung Galaxy
Samsung Galaxy is a group of tools. They make phones and tablets. Some can even fold. These tools help us talk and play. They are very helpful to us. Do you use a phone?
Early Reader · Change the reading level on the articleSamuel Colt
Samuel Colt was an inventor. He made a new kind of gun. It could shoot many times. This helped many people. He was very good at making things. Do you like to build things?
Early Reader · Change the reading level on the articleSamuel Insull
A man named Samuel helped bring light to homes. He helped build ways to send power to cities. This helped many people use lights. He also helped start radio stations. He loved music and art too. Do you like to listen…
Early Reader · Change the reading level on the articleSamuel Sachs
Samuel Sachs helped start a big bank. He worked with his friend. He helped new companies get money. This helped many businesses grow. He was a kind man. Can you name a big bank?
Early Reader · Change the reading level on the articleSamuel Slater
A man named Samuel built big mills. These mills made cloth. He used water to help them work. This helped make many things for people. Do you like wearing cloth?
Early Reader · Change the reading level on the articleSand casting
We can make metal things with sand. First, we pack sand around a shape. Then we pour hot, melted metal in. The metal fills the sand shape. It cools down and gets hard. Now we have a metal part! Can you think of…
Early Reader · Change the reading level on the articleSandy Gall
Sandy Gall was a man who told news. He traveled to many far places. He worked for many years. He helped people in a far land. He was a very busy man. Do you like to hear news?
Early Reader · Change the reading level on the articleSan Francisco Chronicle
The Chronicle is a newspaper. It tells news to people. It is from a big city. It helps us know what is happening. It is very old. Do you like to read news?
Early Reader · Change the reading level on the articleSan Francisco–Oakland Bay Bridge
A big bridge goes over the water. It helps cars get to new places. Many cars use it every day. It helps people visit friends. It is very long and big. Do you like big bridges?
Early Reader · Change the reading level on the articleSanitary engineering
People work to keep us clean. They help move waste away. They also bring us safe water. This keeps us from getting sick. It is very important. Do you like clean water?
Early Reader · Change the reading level on the articleSankei Shimbun
This is a big newspaper in Japan. It tells people the news every day. It is one of the largest papers there. Many people read it to learn things. It helps us know what is happening. Do you like to read news?
Early Reader · Change the reading level on the articleSantiago Metro
The Santiago Metro is a train system. It moves people in a big city. Many people ride the trains every day. It helps us get to places fast. It is a great way to travel. Do you like riding trains?
Early Reader · Change the reading level on the article