An elevator moves things or people from one level to another, and is important to tall structures like skyscrapers. The car of an elevator, in which people ride, is attached to guard rails inside a tall, empty space called a shaft. It is moved by a steel cable that is attached to a large weight that counterbalances it. An electric motor raises and lowers the cable, changing the positions of the car and weight as the elevator moves from floor to floor. (Usually posted inside an elevator are numbers that indicate the car’s weight limit; an elevator motor cannot do its job if a car is a lot heavier than the weight that balances it.)
- What is the tallest building in the world?
- How is steel used in skyscrapers?
- What is the Nobel Prize?
- Why are there different religions and how did they spread?
- What was the Industrial Revolution?
- What is a patent?
- What is the difference between an invention and a discovery?
- Which state was once an independent kingdom?
- Where can you stand in four states at the same time?
- Which state has the most people?
- Which is the largest state in area, and which is the smallest?
- How can you travel across Alaska’s miles of snow?
- Why do states have names and nicknames?
- Is the District of Columbia a state?
- Why do women in some countries wear veils?
- Which states were not organized as territories first?
- How did the United States begin?
- How did we get the United States national anthem?
- What do the stars and stripes on the United States flag mean?
- Why is the bald eagle the official national symbol of the United States?
