I need help plz help me

A solid conducting sphere with radius RR that carries positive charge QQ is concentric with a very thin insulating shell of radi

svetlana [45]

Answer:

$E=0$ at r < R;

$E=\frac{1}{4\pi\epsilon}\frac{Q}{r^{2}}$ at 2R > r > R;

$E=\frac{1}{4\pi\epsilon} \frac{2Q}{r^{2}}$ at r >= 2R

Explanation:

Since we have a spherically symmetric system of charged bodies, the best approach is to use Guass' Theorem which is given by,

$\int {E} \, dA=\frac{Q_{enclosed}}{\epsilon}$ (integral over a closed surface)

where,

$E$ = Electric field

$Q_{enclosed}$ = charged enclosed within the closed surface

$\epsilon$ = permittivity of free space

Now, looking at the system we can say that a sphere(concentric with the conducting and non-conducting spheres) would be the best choice of a Gaussian surface. Let the radius of the sphere be r .

at r < R,

$Q_{enclosed}$ = 0 and hence $E$ = 0 (since the sphere is conducting, all the charges get repelled towards the surface)

at 2R > r > R,

$Q_{enclosed}$ = Q,

therefore,

$E\times4\pi r^{2}=\frac{Q_{enclosed}}{\epsilon}$

(Since the system is spherically symmetric, E is constant at any given r and so we have taken it out of the integral. Also, the surface integral of a sphere gives us the area of a sphere which is equal to $4\pi r^{2}$ )

or, $E=\frac{1}{4\pi\epsilon}\frac{Q}{r^{2}}$

at r >= 2R

$Q_{enclosed}$ = 2Q

Hence, by similar calculations, we get,

$E=\frac{1}{4\pi\epsilon} \frac{2Q}{r^{2}}$

4 0

3 years ago

I tried the experiment of dropping candy into a liter of soda and caused a big explosion of foamy soda. Is that a physical or Ch

Aleks04 [339]

Answer:

physical change

Explanation:

its a physical change because its still soda it hasn't changed into anything else than what it already is

6 0

3 years ago

3. A bottle of vitamin C contains 100 tablets and weighs 80 g. If the

Elan Coil [88]

Answer:

a

0.57g

b

20.52

c

28.5

Explanation:

a

The bottle weighs 80g with tablets

If the bottle alone weighs 23g, the tablets weigh 57g

100 tablets weigh 57g, 1 tablet weighs 0.57g

b

0.57g is one tablet, so to achieve 36 tablets we must multiply by 36

0.57 multiplied by 36 is 20.52

c

To find 50 tablets we can use the same method we used before or a slightly faster method

100 tablets is 57g, so all we have to do is halve to find 50

57 divided by 2 is 28.5

4 0

2 years ago

Birdman is flying horizontally at a

den301095 [7]

Answer:

68 m

Explanation:

Given that the horizontal velocity of the birdman = 17 m/s and

the height, h= 78 m.

The gravitational force is acting in the downward direction, so it will not change the horizontal speed.

The horizontal speed will remains be constant and will be equal to the initial horizontal speed of the turd.

Initially, the turd was also flying horizontally with the birdman, so the initial velocity of the turd is the same as the horizontal velocity of the birdman, i.e In the horizontal direction, $u_0=17$ m/s.