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2 years ago

What is the frequency of microwaves of wavelength 3 cm?

Physics

1 answer:

tiny-mole [99]2 years ago

4 0

Answer:

10 GHz

Explanation:

Applying,

v = λf.................... Equation 1

Where v = speed of microwave, λ = wavelength, f = frequency.

make f the subject of the equation

f = v/λ................ Equation 2

Note: Microwave is an electromagnetic wave, and all electromagnetic wave have the same speed, which is 3×10⁸ m/s

From the question,

Given: λ = 3 cm = 0.03 m

Constant; v = 3×10⁸ m/s

Substitute these values into equation 2

f = 3×10⁸/(0.03)

f = 10¹⁰ Hz

f = (10¹⁰/10⁹) GHz

f = 10 GHz

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Deep in the interiors of the giant planets, water is still a liquid even though the temperatures are tens of thousands of degree

Nataliya [291]

Answer:

High pressure inside the giant planet

Explanation:

As we move in the interior of the giant planet, the pressure and temperature in the interior of the planet increases. Since, the giant planets have hardly any solid surface and thus they are mostly constituted of atmosphere.

Also, the gravitational forces keep even the lightest of the matter bound in it contributing to the large mass of the planet.

If we look at the order of the magnitude of the temperature of these giant planets than nothing should be able to stay in liquid form but as the depth of the planet increases with the increase in temperature, pressure also increases which keeps the particle of the matter in compressed form.

Thus even at such high order of magnitude water is still found in liquid state in the interior of the planet.

7 0

3 years ago

Explain what an exoskeleton is and what it is made of.

sergey [27]

The bodies of arthropods are supported, not by internal bones, but by a hardened exoskeleton made of chitin, a substance produced by many non-arthropods as well. In arthropods, the nonliving exoskeleton is like a form-fitting suit of armor. It is produced by the "skin" and then hardens into a protective outer-covering.

5 0

3 years ago

If you wanted the pitch of a horn to drop relative to an observer, which way would you move the horn, relative to where that obs

Vladimir [108]

We assume that horn releases sound of constant frequency. In order for observer to observe different frequency either horn or observer or both must move.

This happens due to Doppler effect. It states that when position of source of sound and observer relative to each other changes, the observed frequency also changes. If the source emits sound of constant frequency than observed frequency will be either higher or lower than original.

When distance between source and observer increases the observed frequency will be lower. This is because same number of sound waves must cover greater distance so they have greater wavelength.
When distance between source and observer decreases the observed frequency will be higher. This is because same number of sound waves must cover smaller distance so they have smaller wavelength.

Wavelength and frequency are inversely proportional meaning when one increases the other drecreases.

From this explanation we can find answer for our question. If we wanted the pitch of a horn to drop relative to an observer we need to move horn away from an observer.

3 0

2 years ago

A rock is thrown off a 50.0 m high cliff. How fast must the rock leave the cliff top to land on level ground below, 90 m from th

blagie [28]

Answer:

The rock must leave the cliff at a velocity of 28.2 m/s

Explanation:

The position vector of the rock at a time t can be calculated using the following equation:

r = (x0 + v0x · t, y0 + 1/2 · g · t²)

Where:

r = position vector at time t.

x0 = initial horizontal position.

v0x = initial horizontal velocity.

t = time.

g = acceleration due to gravity (-9.81 m/s² considering the upward direction as positive).

Please, see the attached figure for a graphical description of the problem. Notice that the origin of the frame of reference is located at the edge of the cliff so that x0 and y0 = 0.

When the rock reaches the ground, the position vector will be (see r1 in the figure):

r1 = (90 m, -50 m)

Then, using the equation of the vector position written above:

90 m = x0 + v0x · t

-50 m = y0 + 1/2 · g · t²

Since x0 and y0 = 0:

90 m = v0x · t

-50 m = 1/2 · g · t²

Let´s use the equation of the y-component of the vector r1 to find the time it takes the rock to reach the ground and with that time we can calculate v0x:

-50 m = 1/2 · g · t²

-50 m = -1/2 · 9.81 m/s² · t²

-50 m / -1/2 · 9.81 m/s² = t²

t = 3.19 s

Now, using the equation of the x-component of r1:

90 m = v0x · t

90 m = v0x · 3.19 s

v0x = 90 m / 3.19 s

v0x = 28.2 m/s

8 0

3 years ago

A sound wave travels in air toward the surface of a freshwater lake and enters into the water. The frequency of the sound does n

Shkiper50 [21]

Answer:

Explanation:

velocity of sound in air at 20⁰C is 343 m /s

velocity of sound in water at 20⁰C is 1481 m /s

The wavelength of the sound is 2.86 m in the air so its frequency

= 343 / 2.86 = 119.93 .

This frequency of 119.93 will remain unchanged in water .

wavelength in water = velocity in water / frequency

= 1481 / 119.93

= 12. 35 m .

7 0

2 years ago