- #1

donaldparida

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- 10

## Homework Statement

:[/B]A person aims a gun at a bird from a point at a horizontal distance of 100m. If the gun can impart a speed of 500m/s to the bullet , then above what height of the bird he should aim his gun to hit it ?

## Homework Equations

: [/B][itex]H_{max}=\frac{u^2\sin^2\theta}{2g}[/itex]

[itex]R=\frac{u^2\sin2\theta}{g}[/itex]

3. The Attempt at a Solution :

Range= [itex]R=\frac{u^2\sin2\theta}{g}[/itex][itex]\implies \sin2\theta=\frac{Rg}{u^2}[/itex][itex]\implies \sin2\theta=\frac{1}{250}[/itex][itex]\implies 2\theta=\sin^{-1}(\frac{1}{250})[/itex][itex]\implies \theta\approx 0.11[/itex]Maximum height=[itex]H=\frac{u^2sin^2\theta}{2g}[/itex][itex]\implies H=0.04 m [/itex]The correct answer is 20 m. Where have i gone wrong?

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