What is a mixture of rock and mineral fragments, organic matter, air, and water called?

Which of the following statements is TRUE? The side of the Moon facing away from the Earth is in perpetual darkness. The Moon is

Ivanshal [37]

Answer:

The Moon's distance from the Earth varies during its orbit

Explanation:

The correct statement is ,The Moon's distance from the Earth varies during its orbit.

Important point regarding moon:

1 .Moon is a natural satellite of the earth.

2. Moon is the fifth largest satellite in solar system.

3.Second densest satellite in solar system.

4.Moon rotates about earth.

5.Moon is an astronomical body .

5 0

2 years ago

The angular momentum of a flywheel having a rotational inertia of 0.140 kg ·m2 about its central axis decreases from 3.00 to 0.8

Rasek [7]

Answer

given,

I = 0.140 kg ·m²

decrease from 3.00 to 0.800 kg ·m²/s in 1.50 s.

a) $\tau = \dfrac{\Delta L}{\Delta t}$

$\tau = \dfrac{0.8-3}{1.5}$

τ = -1.467 N m

b) angle at which fly wheel will turn

$\theta= \omega t +\dfrac{1}{2}\alpha t^2$

$\theta= \dfrac{L}{I} t +\dfrac{1}{2}\dfrac{\tau}{I}t^2$

$\theta= \dfrac{3}{0.14}\times 1.5+\dfrac{1}{2}\dfrac{-1.467}{0.14}\times 1.5^2$

θ = 20.35 rad

c) work done on the wheel

W = τ x θ

W = -1.467 x 20.35 rad

W = -29.86 J

d) average power of wheel

$P_{av} =-\dfrac{W}{t}$

$P_{av} =-\dfrac{(-29.86)}{1.5}$

$P_{av} =19.91\ W$

7 0

2 years ago

Read 2 more answers

A microwave oven operating at 1.22 × 108 nm is used to heat 165 mL of water (roughly the volume of a teacup) from 23.0°C to 100.

ANTONII [103]

<u>Answer:</u> The number of photons are $3.7\times 10^8$

<u>Explanation:</u>

We are given:

Wavelength of microwave = $1.22\times 10^8nm=0.122m$ (Conversion factor: $1m=10^9nm$ )

To calculate the energy of one photon, we use Planck's equation, which is:

$E=\frac{hc}{\lambda}$

where,

h = Planck's constant = $6.625\times 10^{-34}J.s$

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength = 0.122 m

Putting values in above equation, we get:

$E=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{0.122m}\\\\E=1.63\times 10^{-24}J$

Now, calculating the energy of the photon with 88.3 % efficiency, we get:

$E=1.63\times 10^{-24}\times \frac{88.3}{100}=1.44\times 10^{-24}J$

To calculate the mass of water, we use the equation:

$Density=\frac{Mass}{Volume}$

Density of water = 1 g/mL

Volume of water = 165 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{165mL}\\\\\text{Mass of water}=165g$

To calculate the amount of energy of photons to raise the temperature from 23°C to 100°C, we use the equation:

$q=mc\Delta T$

where,

m = mass of water = 165 g

c = specific heat capacity of water = 4.184 J/g.°C

$\Delta T$ = change in temperature = $T_2-T_1=100^oC-23^oC=77^oC$

Putting values in above equation, we get:

$q=165g\times 4.184J/g.^oC\times 77^oC\\\\q=53157.72J$

This energy is the amount of energy for 'n' number of photons.

To calculate the number of photons, we divide the total energy by energy of one photon, we get:

$n=\frac{q}{E}$

q = 53127.72 J

E = $1.44\times 10^{-24}J$

Putting values in above equation, we get:

$n=\frac{53157.72J}{1.44\times 10^{-24}J}=3.7\times 10^{28}$

Hence, the number of photons are $3.7\times 10^8$

4 0

3 years ago

Traveling waves are generated on a string fixed at both ends. The string has a length L, a linear mass density m, and a tension

bagirrra123 [75]

Answer: d. I or II

Explanation: A traveling wave has speed that depends on characteristics of a medium. Characteristics like linear density (μ), which is defined as mass per length.

Tension or Force ( $F_{T}$ ) is also related to the speed of a moving wave.

The relationship between tension and linear density and speed is ginve by the formula:

$|v|=\sqrt{\frac{F_{T}}{\mu} }$

So, for the traveling waves generated on a string fixed at both ends described above, ways to increase wave speed would be:

1) Increase Tension and maintaining mass and length constant;

2) Longer string will decrease linear density, which will increase wave speed, due to their inversely proportional relationship;

Then, ways to increase the wave speed is

I. Using the same string but increasing tension

II. Using a longer string with the same μ and T.

8 0

2 years ago

A harmonic force of maximum value 25 N and frequency of 180 cycles>min acts on a machine of 25 kg mass. Design a support syst

kramer

Answer:

registrar y de h2rhrjlekeek tert2h2jwkwlwlwlwlwlwñlwk

3 0

2 years ago