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An open knife edge of mass 200g is dropp...

An open knife edge of mass 200g is dropped from height 5m on a cardboar. If the knife edge penetrates a distance 2 m into the cardboard. Find the average resistance offered by the cardboar to the knife edge (in N). `(g = 10 m//s^(2))`

A

`7N`

B

`25N`

C

`35N`

D

None

Text Solution

Verified by Experts

The correct Answer is:
A
`u =sqrt(2gh)`,using `v^(2) -u^(2) =2as` retardation due to air resistance `a^(1) = g +a`
Force due to air resistance `=Ma` .
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