# What is a speed graph

## speed

The speedometer in the car shows the current speed.

The speed indicates how fast or how slow something is. The speed is also called "pace". In the car or on the motorcycle, the "speedometer" shows the speed. It is usually given in the unit of measurement kilometers per hour, abbreviated to km / h.

In physics, speed means that the distance covered changes in a certain time. If a speed changes itself, this is called acceleration.

Speed ​​plays an important role in many sports. The fastest wins in the 100-meter run, car races, marathons and many other competitions. In road traffic, however, there is often a speed limit, i.e. a speed limit. This is to avoid dangerous situations. With us you are normally allowed to drive a maximum of 50 km / h in a locality, in some residential areas even only 30 km / h.

### What are the highest speeds?

No other animal can match the speed of a peregrine falcon.

In the 100-meter run, the sprinter Usain Bolt reached a top speed of almost 45 km / h. Many can hardly do that by bike. A Formula 1 car can reach top speeds of over 360 km / h. The Shinkansen maglev train in Japan can go as fast as 600 km / h. The speed record for an unmanned test aircraft is in the air: the Boeing X-43 flew at around 11,000 km / h. Only rockets are more than twice as fast to get into space and stay there.

There are also particularly quick representatives in the animal kingdom. The peregrine falcon reaches the highest speed of all animals in a nosedive: it reaches about 350 km / h. The fastest animal on the ground is the cheetah because it can run 110 km / h, but only for a short time. The sailfish is the record holder in the water. It is just as fast as the cheetah on land.

The absolute highest speed that is conceivable is the speed of light. The light covers almost 300,000 kilometers in just one second! That is so fast that it is no longer stated in km / h because the number would then be even bigger. The almost infinite distances in space are therefore given in light years. A light year is the distance that light travels in one year. That is about 9,461,000,000,000 kilometers, i.e. 9.461 trillion kilometers.

### What is the speed of sound?

A tone moves at the speed of sound. When a worker is hammering and you watch him close up, you can see and hear the blow at the same time. But over a long distance, the sound comes behind. This is because sound is slower than light in air. The speed of sound in the air is 1236 km / h. That corresponds to 343 meters per second. One writes 343 m / s. So if the hammer blow can be heard a second later, then the worker is about 350 meters away from the listener.

The speed of sound can also be used to calculate how far away a thunderstorm is. Every second that lies between lightning and thunder means that the center of the thunderstorm is about 350 meters away.

• The cheetah is the fastest animal in the country.

• The sailfish has a large dorsal fin like a sail. If he chases other fish at lightning speed, he folds this fin.

• The distance to the thunderstorm can be calculated with the speed of sound.

There are also other search results for “Speed” from Blind Cow and Ask Finn.

The Klexikon is like a Wikipedia for children and schoolchildren. The most important things explained simply, with definition, many pictures and maps in over 3000 articles. Basic knowledge suitable for children, everything easy to understand and good for presentations in school.