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A jet water, whose cros section is 'a' s...

A jet water, whose cros section is 'a' strikes a wall making an angle `theta` with normal and elastically rebounds. The velocity of water of density 'd' is v. Force exerted on wall is :-

A

`2 av^(2) d cos theta`

B

` 2 av^(2) d sin theta`

C

`2 av d cos theta`

D

av d `cos theta`

Text Solution

Verified by Experts

The correct Answer is:
A
`Deltap=2mv cos theta`
`F=(delp)/(delt)=(2v cos theta)(delm)/(delt)`

The mass crossing an area in t would be
`vxxtxxAxxdel=m`
`therefore (dm)/(dt)=v_(Ad)`
`therefore F=2av^(2)delcps theta`
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