All categories

3 years ago

How to light prodeced by nature

1 answer:

4 0

Natural sources of light include our sun and other stars, where the source of energy is nuclear energy (recall that the moon does not produce light but merely reflects sunlight), lightning, where the source is electrical, and fire, where the energy source is chemical.

You might be interested in

The electron beam inside a television picture tube is 0.40 {\rm mm} in diameter and carries a current of 50 {\rm \mu A}. This el

Harrizon [31]

Answer:

A.3.13x10^14 electrons

B.330A/m²

C.9.11x10^5N/C

D. 0.23W

.pls see attached file for explanations

8 0

3 years ago

The temperature of air changes from 0 to 10°C while its velocity changes from zero to a final velocity, and its elevation change

aliya0001 [1]

Answer:

Final velocity = 119.83 m/s

Final elevation = 731.9 m

Explanation:

We are told that temperature of air changes from 0 to 10°C

Thus;

Change in temperature; ΔT = 10 - 0 = 10°C

Also, its velocity changes from zero to a final velocity. Thus;

v1 = 0 m/s

v2 is unknown

Also, its elevation changes from zero to a final elevation.

So, z1 = 0 and z2 is unknown

Now, we want to find v2 and z2 when the internal, kinetic and potential energy are equal.

Thus Equating the formula for both kinetic and internal energy gives;

½m(v2² - v1²) = mc_v•ΔT

m will cancel out and v1 is zero to give;

v2² = 2c_v•ΔT

v2 = √(2c_v•ΔT)

Where c_v is specific heat of constant volume of air with a constant value of 718 J/Kg.K

Thus;

v2 = √(2 × 718 × 10)

v2 = √14360

v2 = 119.83 m/s

To find z2, we will equate potential energy formula to that of the internal energy.

Thus;

mg(z2 - z1) = mc_v•ΔT

m will cancel out and since z1 is zero, then we have;

z2 = (c_v•ΔT)/g

z2 = 718 × 10/9.81

z2 = 731.9 m

4 0

4 years ago

To make a given sound seem twice as loud, how should a musician change the intensity of the sound?

Serhud [2]

Answer:

C. Quadruple the intensity

Explanation:

The intensity of the sound is proportional to square of amplitude of the sound.

I ∝ A²

$\frac{I_1}{A_1^2} = \frac{I_2}{A_2^2}\\\\I_2 = \frac{I_1A_2^2}{A_1^2}$

When the given sound is twice loud as the initial value, then the new amplitude is twice the former.

A₂ = 2A₁

$I_2 = \frac{I_1A_2^2}{A_1^2} \\\\I_2 = \frac{I_1(2A_1)^2}{A_1^2} \\\\I_2 = \frac{4I_1A_1^2}{A_1^2}\\\\ I_2 = 4I_1$

Thus, to make a given sound seem twice as loud, the musician should Quadruple the intensity

3 0

3 years ago

A visible light has a wavelength of 727.3 nm. Determine its frequency, energy per photon, and color.

Snezhnost [94]

Answer:

$f=4.12\times 10^{14}\ Hz$ and $E=2.73\times 10^{-19}\ J$

Explanation:

The wavelength of a visible light is 727.3 nm.

$727.3\ nm=727.3 \times 10^{-9}\ m$

The formula is as follows :

$c=f\lambda$

f is the frequency of the visible light

$f=\dfrac{c}{\lambda}\\\\f=\dfrac{3\times 10^8}{727.3 \times 10^{-9}}\\\\f=4.12\times 10^{14}\ Hz$

Energy of a photon is given by :

E = hf, h is Planck's constant

$E=6.63\times 10^{-34}\times 4.12\times 10^{14}\\\\E=2.73\times 10^{-19}\ J$

Red color has a frequency of $4.12\times 10^{14}\ Hz$ and energy per photon is $2.73\times 10^{-19}\ J$ .

3 0

3 years ago

How many millimeters are in 8 meters?

frutty [35]

Explanation:

8 m × (1000 mm / m) = 8000 mm

3 0

3 years ago