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4 years ago

How many photons with 10 ev are required to produce 20 joules of energy?

1 answer:

7 0

Electron Volts (eV) are units of energy that are convenient for use in describing energy scales of particles. One electron Volt is equal to 1.6 x 10^-19 Joules. Therefore, ten electron Volts are equal to 1.6 x 10^-18 Joules. In order to produce 20 Joules of energy from 10 eV photons, we would need 20 / (1.6 x 10^-18) = 1.25 x 10^19 photons.

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What happens when exhale

polet [3.4K]

When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.

4 0

4 years ago

Read 2 more answers

The radius of the aorta is «10 mm and the blood flowing through it has a speed of about 300 mm/s. A capillary has a radius of ab

stealth61 [152]

Answer:

(I). The effective cross sectional area of the capillaries is 0.188 m².

(II). The approximate number of capillaries is $3.74\times10^{9}$

Explanation:

Given that,

Radius of aorta = 10 mm

Speed = 300 mm/s

Radius of capillary $r=4\times10^{-3}\ mm$

Speed of blood $v=5\times10^{-4}\ m/s$

(I). We need to calculate the effective cross sectional area of the capillaries

Using continuity equation

$A_{1}v_{1}=A_{2}v_{2}$

Where. v₁ = speed of blood in capillarity

A₂ = area of cross section of aorta

v₂ =speed of blood in aorta

Put the value into the formula

$A_{1}=A_{2}\times\dfrac{v_{2}}{v_{1}}$

$A_{1}=\pi\times(10\times10^{-3})^2\times\dfrac{300\times10^{-3}}{5\times10^{-4}}$

$A_{1}=0.188\ m^2$

(II). We need to calculate the approximate number of capillaries

Using formula of area of cross section

$A_{1}=N\pi r_{c}^2$

$N=\dfrac{A_{1}}{\pi\times r_{c}^2}$

Put the value into the formula

$N=\dfrac{0.188}{\pi\times(4\times10^{-6})^2}$

$N=3.74\times10^{9}$

Hence, (I). The effective cross sectional area of the capillaries is 0.188 m².

(II). The approximate number of capillaries is $3.74\times10^{9}$

3 0

3 years ago

A circular coil of wire, with N turns of radius a, is located in the field of an electromagnet. The magnetic field is perpendicu

weeeeeb [17]

Answer:

they are going to attract

Explanation:

7 0

3 years ago

Willing to give out Brainliest: 3.00 m^3 of water is at 20.0°C If you raise its temperature to 60.0°C, by how much will its volu

lozanna [386]

Answer:

The answer is below

Explanation:

Charlee's law states that the volume of a gas is directly proportion to the temperature of the gas at constant pressure. That is:

V = kT, where V = volume and T = temperature, k = constant. Therefore:

V / T = k

$\frac{V_1}{T_1}=\frac{V_2}{T_2}$

Given that: $V_1=3\ m^3, T_1=20^oC=(20 + 273)K=293\ k,T_2=60^oC=(60 + 273)K=333\ k.\\\\\frac{V_1}{T_1}=\frac{V_2}{T_2}\\\\\frac{3}{293}=\frac{V_2}{333} \\\\V_2=\frac{3}{293}*333\\\\V_2=3.41\ m^3\\$