What is kendo (Martial art)

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kendo is a Japanese form of fencing with two handed bamboo staves instead of swords.
This martial aims to develop self control. The fighters wear long, black skirts, padded gloves, light armour and helmet.
They attempt to score points by striking their Rival in a ritual contest. Even the Samurai the Warriors of ancient Japan were trained in kendo.

why are racing cars faster than ordinary cars

Racing cars are so built that they are faster than ordinary cars.

They have a streamlined body to cut the resistance of the air, big wider tyres to give extra grip at high speed, low shining body and powerful engine. The material used to make the body are also ultralight and so that it offer less resistance at high speed.