Question

On earth the weight of a boy is 30 kgf. What will be his weight on moon ? Give your ans. in S.I unit.​

Answer 1

Answer :-

Weight of the boy on moon will be 49 Newtons .

Explanation :-

We have (for earth) :-

→ Weight of the boy = 30 kgf

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We have to calculate the weight of the boy on moon in S.I. unit . (in Newtons)

So firstly, let's convert the given weight of the boy on earth from "kilograms-force" (kgf) to "Newtons" (N) :-

⇒ 1 kgf = 9.8 N

⇒ 30 kgf = 30(9.8) N

⇒ 294 N

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We know that weight of an object on moon is 1/6th of it's weight on earth. So, we have :-

Wₘ = Wₑ/6

⇒ Wₘ = 294/6

⇒ Wₘ = 49 N

Answer 2

Given :-

Weight of a boy in kgf = 30

To Find :-

Weight on moon

Solution :-

We know that

1 N = 1/9.8 kgf

And

1 kgf = 9.8 N

30 kgf = 9.8 × 30

30 kgf = 98/10 × 30

30 kgf = 98 × 3

30 kgf = 294 N

Now

Weight on Earth = 6 × Weight on moon

294 = 6 × Weight on moon

294/6 = Weight on moon

49 = Weight on moon