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3 years ago

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izes water on the surface of Mars? a. Billions of years ago there were lakes and rivers on the surface of Mars, but none exist t

oday. b. There is no evidence that water ever existed on the surface of Mars. c. There have been lakes and ri

1 answer:

Tanzania [10]3 years ago

6 0

Answer:

The answer is a.

Explanation: Billions of years ago, there were lakes and rivers in the surface of mars because mars had a denser atmosphere and higher surface temperatures which allowed a vast amount of liquid water on the surface. Recently, most of the water on mars today exist as ice.

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Two transverse waves travel along the same taut string. Wave 1 is described by y1(x, t) = A sin(kx - ωt), while wave 2 is descri

Vadim26 [7]

Answer:

6) Wave 1 travels in the positive x-direction, while wave 2 travels in the negative x-direction.

Explanation:

What matters is the part $kx \pm \omega t$ , the other parts of the equation don't affect time and space variations. We know that when the sign is - the wave propagates to the positive direction while when the sign is + the wave propagates to the negative direction, but <em>here is an explanation</em> of this:

For both cases, + and -, after a certain time $\delta t$ ( $\delta t >0$ ), the displacement <em>y</em> of the wave will be determined by the $kx\pm\omega (t+\delta t)$ term. For simplicity, if we imagine we are looking at the origin (x=0), this will be simply $\pm \omega (t+\delta t)$ .

To know which side, right or left of the origin, would go through the origin after a time $\delta t$ (and thus know the direction of propagation) we have to see how we can achieve that same displacement <em>y</em> not by a time variation but by a space variation $\delta x$ (we would be looking where in space is what we would have in the future in time). The term would be then $k(x+\delta x)\pm\omega t$ , which at the origin is $k \delta x \pm \omega t$ . This would mean that, when the original equation has $kx+\omega t$ , we must have that $\delta x>0$ for $k\delta x+\omega t$ to be equal to $kx+\omega\delta t$ , and when the original equation has $kx-\omega t$ , we must have that $\delta x$ for $k\delta x-\omega t$ to be equal to $kx-\omega \delta t$

<em>Note that their values don't matter, although they are a very small variation (we have to be careful since all this is inside a sin function), what matters is if they are positive or negative and as such what is possible or not .</em>

<em />

In conclusion, when $kx+\omega t$ , the part of the wave on the positive side ( $\delta x>0$ ) is the one that will go through the origin, so the wave is going in the negative direction, and viceversa.

4 0

3 years ago

Brainliest if correct Question 1 of 10

Artyom0805 [142]

Answer:

B

Explanation:

7 0

2 years ago

90cm uniform lever has a load 30N suspended at 15cm from one of it's end. If the fulcrum is at the center of gravity. The force

solniwko [45]

Answer: F = 20 N

Explanation:

I will ASSUME that the fulcrum is at the center of gravity of the lever arm, This means that the lever arm itself creates no moment about the fulcrum because there is no moment arm for that particular force.

To solve, we sum moments about any convenient point to zero (zero because there is no acceleration in the F = ma equation)

The easiest convenient point is the fulcrum

30((90/2) - 15) - F(90/2) = 0

30(30) = F(45)

F = 900/45 = 20 N

3 0

2 years ago

The escape velocity of any object from Earth is 11.2 km/s. (a) Express this speed in m/s and km/h. (b) At what temperature would

natima [27]

Answer:

a ) 11.1 *10^3 m/s = 39.96 Km/h

b) T_{o2} =1.58*10^5 K

Explanation:

a) $v_{es} =v_{rms}$ = 11.1 km/s =11.1 *10^3 m/s = 39.96 Km/h

b)

M_O2 = 32.00 g/mol =32.0*10^{-3} kg/mol

gas constant R = 8.31 j/mol.K

$v_{rms} = \sqrt{ \frac{3RT}{M}}$

So, $v_{rms,o2} =\sqrt{ \frac{3RT_{o2}}{M_{o2}}}$

multiply each side by M_{o2}, so we have

$v_{rms,o2}^2 *M_{o2} =3RT_{o2}$

solving for temperature T_{o2}

$T_{o2} = \frac{v_{rms,o2}^2 *M_{o2}}{3R}$

In the question given, $v_{rms} =v_{es}$

$T_{o2} = \frac{(11.1*10^3)^2 *32.0*10^{-3}}{3*8.31}$

T_{o2} =1.58*10^5 K

7 0

3 years ago

What is the relationship between the wavelength of light and the frequency of light?

Elden [556K]

Answer:

The wavelength and frequency of light are closely related. The higher the frequency, the shorter the wavelength. Because all light waves move through a vacuum at the same speed, the number of wave crests passing by a given point in one second depends on the wavelength.

Explanation:

The frequency of a light wave is how many waves move past a certain point during a set amount of time -- usually one second is used. Frequency is generally measured in Hertz, which are units of cycles per second. Color is the frequency of visible light, and it ranges from 430 trillion Hertz (which is red) to 750 trillion Hertz (which is violet). Waves can also go beyond and below those frequencies, but they're not visible to the human eye. For instance, radio waves are less than one billion Hertz; gamma rays are more than three billion billion Hertz.Wave frequency is related to wave energy. Since all that waves really are is traveling energy, the more energy in a wave, the higher its frequency. The lower the frequency is, the less energy in the wave. Following the above examples, gamma rays have very high energy and radio waves are low-energy. When it comes to light waves, violet is the highest energy color and red is the lowest energy color. Related to the energy and frequency is the wavelength, or the distance between corresponding points on subsequent waves. You can measure wavelength from peak to peak or from trough to trough. Shorter waves move faster and have more energy, and longer waves travel more slowly and have less energy.Aside from the different frequencies and lengths of light waves, they also have different speeds. In a vacuum, light waves move their fastest: 186,000 miles per second (300,000 kilometers per second). This is also the fastest that anything in the universe moves. But when light waves move through air, water or glass, they slow down. That's also when they bend and refract.

6 0

3 years ago