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What is polarization. How can we remove it?

weqwewe [10]

Polarization is the action of restricting the vibrations of a transverse wave, especially light, wholly or partially to one direction .

7 0

3 years ago

Io experiences tidal heating primarily because __________.

Inga [223]

Answer:

the orbit of Io around Jupiter causes the tidal heating.

Explanation:

Io's elliptical orbit causes the tidal force to vary as it orbits Jupiter.

Because Jupiter is a very massive planet, it has a very large gravitational pull on its moons, so the side of Io facing the planet is experiencing a greater gravitational pull than the opposite side. This causes a distortion in the shape of the Io, and a friction that causes the tidal heating.

This friction generates heat currents, which is what makes Io the place with the most volcanic activity in the solar system.

7 0

3 years ago

Potassium is a crucial element for the healthy operation of the human body. Potassium occurs naturally in our environment and th

gregori [183]

Complete Question

Potassium is a crucial element for the healthy operation of the human body. Potassium occurs naturally in our environment and thus our bodies) as three isotopes: Potassium-39, Potassium-40, and Potassium-41. Their current abundances are 93.26%, 0.012% and 6.728%. A typical human body contains about 3.0 grams of Potassium per kilogram of body mass. 1. How much Potassium-40 is present in a person with a mass of 80 kg? 2. If, on average, the decay of Potassium-40 results in 1.10 MeV of energy absorbed, determine the effective dose (in Sieverts) per year due to Potassium-40 in an 80- kg body. Assume an RBE of 1.2. The half-life of Potassium-40 is $1.28 * 10^9$ years.

Answer:

The potassium-40 present in 80 kg is $Z = 0.0288 *10^{-3}\ kg$

The effective dose absorbed per year is $x = 2.06 *10^{-24}$ per year

Explanation:

From the question we are told that

The mass of potassium in 1 kg of human body is $m = 3g= \frac{3}{1000} = 3*10^{-3} \ kg$

The mass of the person is $M = 80 \ kg$

The abundance of Potassium-39 is 93.26%

The abundance of Potassium-40 is 0.012%

The abundance of Potassium-41 is 6.78 %

The energy absorbed is $E = 1.10MeV = 1.10 *10^{6} * 1.602 *10^{-19} = 1.7622*10^{-13} J$

Now 1 kg of human body contains $3.0*10^{-3}\ kg$ of Potassium

So 80 kg of human body contains k kg of Potassium

=> $k = \frac{ 80 * 3*10^{-3}}{1}$

$k = 0.240\ kg$

Now from the question potassium-40 is 0.012% of the total potassium so

Amount of potassium-40 present is mathematically represented as

$Z = \frac{0.012}{100} * 0.240$

$Z = 0.0288 *10^{-3}\ kg$

The effective dose (in Sieverts) per year due to Potassium-40 in an 80- kg body is mathematically evaluated as

$D = \frac{E}{M}$

Substituting values

$D = \frac{1.7622*10^{-13}}{80}$

$D = 2.2*10^{-15} J/kg$

Converting to Sieverts

We have

$D_s = REB * D$

$D_s = 1.2 * 2.2 *10^{-15}$

$D_s = 2.64 *10^{-15}$

So

for half-life ( $1.28 *10^9 \ years$ ) the dose is $2.64 *10^{-15}$

Then for 1 year the dose would be x

=> $x = \frac{2.64 *10^{-15}}{1.28 * 10^9}$

$x = 2.06 *10^{-24}$ per year

7 0

4 years ago

A standing wave with 5 loops is created on a string that is 0.75 m long. If the

Alex

wave velocity = frequency × wavelength

300 = frequency × 0.75

Frequency = 300÷0.75 = 400 HZ

6 0

3 years ago

A soccer player kicks a ball horizontally at 25.0 m/s from a bridge, and the ball hits

san4es73 [151]

Answer: 11.025 meters.

Explanation:

Ok, we know that the initial velocity is only horizontal, so it does not affect the vertical problem.

Looking only at the vertical problem (because we want to know how high is the bridge) we have that:

The acceleration is the gravitational acceleration, g = 9.8m/s^2

A(t) = -9.8m/s^2

Where the negative sign is because this acceleration is downwards.

For the vertical velocity we integrate over time, as we do not have an initial vertical velocity, there is no constant of integration.

V(t) = (-9.8m/s^2)*t

For the position we integrate over time again, here the constant of integration is the initial vertical position, H, that is the height of the bridge.

P(t) = 0.5* (-9.8m/s^2)*t^2 + H.

Now we know that the ball hits the ground 1.5s after it was kicked, then:

p(1.5s) = 0m

With that we can find the value of H.

0 = 0.5* (-9.8m/s^2)*(1.5s)^2 + H.

H = 0.5*(9.8m/s^2)*(1.5s)^2 = 11.025m

5 0

3 years ago