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3 years ago

Pure silicon contains approximately 1.0 X 1016 free electrons per cubic meter. (

1 answer:

3 0

A. The formula for mean free time is:

t = V/(4π√2 r²vN)
where
N = 1×10¹⁶ molecules (per m³)
V = 1 m³
r = 111×10⁻⁷m (atomic radius of silicon)

Let's solve for v first:
v = √(3RT/M) = √(3(8.314 m³·Pa/mol·K)(25 + 273 K)/28.1 g/mol Si)
v = 16.26 m/s

t = (1 m³)/(4π√2 (111×10⁻⁷m)²(16.26 m/s)(1×10¹⁶ molecules))
<em>t = 2.81×10⁻9 s</em>

<em>Pure silicon has a high resistivity relative to copper because copper is a conductor, while silicon is a semi-conductor. </em>

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A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves.

san4es73 [151]

To solve this problem it is necessary to apply the concepts related to the principle of superposition and constructive interference, that is to say everything that refers to an overlap of two or more equal frequency waves, which when interfering create a new pattern of waves of greater intensity (amplitude) whose cusp is the antinode.

Mathematically its definition can be given as:

$d sin\theta =m\lambda$

Where

d = Width of the slit

$\theta =$ Angle between the beam and the source

m = Order (any integer) which represent the number of repetition of the spectrum, at this case 1 (maximum respect the wavelength)

Since the point of the theta angle for which the diffraction becomes maximum will be when it is worth one then we have to:

$\lambda = d$

$\lambda = 20cm = 20*10^{-2}m$

Applying the given relation of frequency, speed and wavelength then we will have that the frequency would be:

$f = \frac{v}{\lambda}$

Here the velocity is equal to the speed of light and the wavelength to the value previously found.

$f = \frac{3*10^8}{0.2}$

$f = 1.5Ghz$

Therefore the smallest microwave frequency for which only the central maximum occurs is 1.5Ghz

7 0

3 years ago

Any organism that has a skeletal sytem

Katena32 [7]

Vertebrate is the answer I think.

6 0

2 years ago

Read 2 more answers

A batter hits a baseball m = 0.41 kg from rest with a force of F = 81

WITCHER [35]

Answer:

7.0s

Explanation:

Mass = 0.41kg

F= 81N

t = 0.22s

¤ = 29°

Lo = 86m

From impulse equation,

F*t = m* v

81 * 0.22 = 0.41 * v

Vo = 17.82 / 0.41

Vo = 43.46m/s

Vx= velocity across horizontal plane

Vy = velocity across vertical plane

Vx = Vo * cos ¤

Vy = Vo * sin ¤

Vx = 43.46 * cos 30° = 37.64 m/s

Vy = 43.46 sin 30° = 21.73 m/s

Distance travelled across the vertical plane,

L = Lo + Vy *t + ½gt²

0 = 86 + 21.73t - 4.9t²

4.9t² - 21.73t - 86 = 0

Solving for t in the quadratic equation,

t = 6.96 or -10.04

Using the positive root since time can't be negative, t = 6.96 approximately 7.0s

4 0

3 years ago

Whats the measure of how much energy a sound wave carries, the loudness of a sound?

musickatia [10]

Decibels I believe? I’m not 100% sure

6 0

3 years ago

A common way to measure the distance to lightning is to start counting, one count per second, as soon as you see the flash. Stop

AURORKA [14]

Answer:

d = 1.07 mile

Explanation:

The rationale for this method is that the speed of light is much greater than the speed of sound, the definition of speed in uniform motion is

v = d / t

d = v t

the speed of sound is worth

v = 343 m / s

Therefore, the speed of sound must be multiplied by time to do this, all the units must be in the same system, as the distance in miles is requested

v = 343 m/s (1mile/1609 m) (3600s/1 h) = 343 (2.24) = 767.4 mile/h

v = 343 m / s (1 mile / 1609 m) = 0.213, mile/ s

If the measured time is t = 5s we multiply it by the speed

we substitute

d = 0.213 5

d = 1.07 mile

If you want to calculate the speed, this method in general is not widely used, since you must know the distance where the lightning occurred, which is relatively complicated.

8 0

2 years ago