# Answer to Question #4772 in Mechanics | Relativity for Krystian

Question #4772

So I have to tell that my english isn't to good , so i will be able to explain exacly what i need if that will be needed

1) how big power do you need to use to make 1 kg body fly up to 50 meters ?

1) how big power do you need to use to make 1 kg body fly up to 50 meters ?

Expert's answer

First let's find initial velosity of the body required to reach 50m

energy conservation law:

mv^2/2=mgh where m -mass of the body, v - initial velosity, h=50m

hence v=sqrt(2gh)=31 m/s

When making body to move force will do work A=mv^2/2/ where v -initial velosity

So A=1*31^2/2=490,5 joules -& work done to make body fly up to 50m

energy conservation law:

mv^2/2=mgh where m -mass of the body, v - initial velosity, h=50m

hence v=sqrt(2gh)=31 m/s

When making body to move force will do work A=mv^2/2/ where v -initial velosity

So A=1*31^2/2=490,5 joules -& work done to make body fly up to 50m

## Comments

Krystian20.10.11, 19:23Ahh ; / I've made a mistake when translating the question. That should be "How big force"

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