Question

A particle is projected at an angle of 45° from 8 m before the foot of a wall, just touches the top of wall
and falls on the ground on opposite side at a distance 4m from it. The height of wall is :
( 1 ) 2/3 m
( 2 ) 4/3 m
( 3 ) 8/3 m
( 4 ) 3/4 m









plz help ....
Don't write that I don't know......
If u know the answer then help me ...​

Answer 1

( 3 ) 8/3 m

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$\orange{\bigstar}$  Given  $\green{\bigstar}$

A particle is projected at an angle of 45° from 8 m before the foot of a wall, just touches the top of wall  and falls on the ground on opposite side at a distance 4 m from it

$\orange{\bigstar}$  To Find  $\green{\bigstar}$

Height of the wall

$\orange{\bigstar}$  Formula Used  $\green{\bigstar}$

$\pink{\bigstar}\ \; \bf y=xtan\theta\left( 1-\dfrac{x}{R}\right)$

where ,

• x denotes horizontal distance from y to point of projection
• θ denotes angle of projection
• R denotes range
• y denotes height

$\orange{\bigstar}$  Solution  $\green{\bigstar}$

Here , x = 8 m

x₁ = 4 m

Angle of projection , θ = 45°

Height of the wall , y = ? m

Range , R = x + x₁ = 8 + 4

⇒ R = 12 m

Apply formula ,

$\bf y=xtan\theta\left(1-\dfrac{x}{R}\right)\\\\\to \rm y= (8)tan(45^{\circ})\left(1-\dfrac{8}{12} \right)\\\\\to \rm y=8(1)\left( 1-\dfrac{2}{3}\right)\\\\\to \rm y=8\left( \dfrac{1}{3}\right)\\\\\to \bf y=\dfrac{8}{3}\ m\ \; \pink{\bigstar}$

So , Height of the wall = 8/3 m

______________________________

Answer 2

Answer:

( 3 ) 8/3 m

______________________________

\orange{\bigstar}★ Given \green{\bigstar}★

A particle is projected at an angle of 45° from 8 m before the foot of a wall, just touches the top of wall and falls on the ground on opposite side at a distance 4 m from it

\orange{\bigstar}★ To Find \green{\bigstar}★

Height of the wall

\orange{\bigstar}★ Formula Used \green{\bigstar}★

\pink{\bigstar}\ \; \bf y=xtan\theta\left( 1-\dfrac{x}{R}\right)★ y=xtanθ(1−

R

x

)

where ,

x denotes horizontal distance from y to point of projection

θ denotes angle of projection

R denotes range

y denotes height

\orange{\bigstar}★ Solution \green{\bigstar}★

Here , x = 8 m

x₁ = 4 m

Angle of projection , θ = 45°

Height of the wall , y = ? m

Range , R = x + x₁ = 8 + 4

⇒ R = 12 m

Apply formula ,

\begin{gathered}\bf y=xtan\theta\left(1-\dfrac{x}{R}\right)\\\\\to \rm y= (8)tan(45^{\circ})\left(1-\dfrac{8}{12} \right)\\\\\to \rm y=8(1)\left( 1-\dfrac{2}{3}\right)\\\\\to \rm y=8\left( \dfrac{1}{3}\right)\\\\\to \bf y=\dfrac{8}{3}\ m\ \; \pink{\bigstar}\end{gathered}

y=xtanθ(1−

R

x

)

→y=(8)tan(45

∘

)(1−

12

8

)

→y=8(1)(1−

3

2

)

→y=8(

3

1

)

→y=

3

8

m ★

So , Height of the wall = 8/3 m

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