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3 years ago

What will the surface charge density be if the radius of the disk is doubled but its total charge remains the same

Physics

1 answer:

zaharov [31]3 years ago

8 0

Answer:

the new surface charge density = Q/4πr²( initial surface charge density divided by 4)

Explanation:

charge density(surface) = Q/A = charge/area

let r be the initial radius of the disk

therefore, area A = πr²

charge density = Q/πr²

Now that the radius is doubled, let it be represented as R

∴ R = 2r

Recall, charge density = Q/A

A = πR = π(2r)² = 4πr²

the new surface charge density = Q/4πr²

the initial surface charge density divided by 4

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Rama09 [41]

Answer:

Magnification, m = -0.42

Explanation:

It is given that,

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Object distance, u = -20 cm

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Focal length of mirror, f = R/2 = -15 cm (focal length is negative for concave mirror)

Using mirror's formula :

$\dfrac{1}{f}=\dfrac{1}{u}+\dfrac{1}{v}$ , f = focal length of the mirror

$\dfrac{1}{v}=\dfrac{1}{f}+\dfrac{1}{u}$

$\dfrac{1}{v}=\dfrac{1}{-15}+\dfrac{1}{-20}$

v = -8.57 cm

The magnification of a mirror is given by,

$m=\dfrac{-v}{u}$

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3 years ago

3. Solve for y: 14=84 over y what is y

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Answer:6

Explanation:

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2 years ago

n a level football field a football is projected from ground level. It has speed 9.0 m/sm/s when it is at its maximum height. It

Pani-rosa [81]

Answer:

T = 0.225 s

Explanation:

The speed of a projectile at the highest point of its motion is the horizontal speed of the projectile. Considering the horizontal motion with negligible air resistance, we can use the following formula:

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T = Total time of ball in air = ?

R = Horizontal distance covered = 40 m

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3 years ago

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Answer:

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3 years ago

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Salsk061 [2.6K]

Answer:

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Explanation:

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