What are the rules of articles?
Table of Contents
What are the rules of articles?
Definite and Indefinite Articles (a, an, the)
| COUNT NOUNS | NON-COUNT NOUNS | |
|---|---|---|
| Rule #1 Specific identity not known | a, an | (no article) |
| Rule #2 Specific identity known | the | the |
| Rule #3 All things or things in general | (no article) | (no article) |
Why we say an hour?
An hour is the correct one. It is because in the word hour the letter h is not pronounced, therefore when hour is pronounced the first letter sounds like a vowel sound. The general rule is: a) when the first letter of a word is a consonant or sounds like consonant the indefinite article a lies in front of the word.
Why is an hour called an hour?
They are so named from the false belief of ancient authors that the Babylonians divided the day into 24 parts, beginning at sunrise. In fact, they divided the day into 12 parts (called kaspu or “double hours”) or into 60 equal parts.
How much is 1 second in space?
It is defined as the distance that light travels in free space in one second, and is equal to exactly metres (ft)….Use in astronomy.
| Unit | light-second | |
|---|---|---|
| Equivalent distance in | m | m |
| km | 2.998×105 km | |
| Example | Average distance from the Earth to the Moon is about 1.282 light-seconds | |
Why is space referred to as a vacuum?
By definition, a vacuum is devoid of matter. Space is almost an absolute vacuum, not because of suction but because it’s nearly empty. Related: What would happen if you shot a gun in space? That emptiness results in an extremely low pressure.
Do things deteriorate in space?
Launching a spacecraft requires overcoming the Earth’s gravitational pull, but during the upward momentum of leaving the launching pad, the craft will experience up to three times the force of Earth’s gravity. Materials used on the spacecraft cannot break, bend or weaken under such effects.
Do things age in space?
Because astronauts like the ones on the International Space Station (ISS) are moving so quickly, they’re also aging a bit more slowly than the rest of us. Due to a principle of physics known as timedilation, after a six-month stint on the ISS, returning astronauts are just a tiny bit younger than the rest of us.
Is it true that if two pieces of metal touch in space they are permanently stuck?
If two pieces of the same type of metal touch in space, they will bond and be permanently stuck together; this amazing effect is known as cold welding. It happens because the atoms of the individual pieces of metal have no way of knowing that they are different pieces of metal, so the lumps join together.
