Sound—energy<span> we can hear—travels only so far before it soaks away into the world around us. Until electrical </span>microphones<span>were invented in the late 19th century, there was no satisfactory way to send </span>sounds<span> to other places. You could shout, but that carried your words only a little further. You couldn't shout in New York City and make yourself heard in London. And you couldn't speak in 1715 and have someone listen to what you said a hundred years later! Remarkably, such things are possible today: by converting sound energy into electricity and information we can store, microphones make it possible to send the sounds of our voices, our music, and the noises in our world to other places and other times. How do microphones work? Let's take a closer look!</span>
Answer:
A <em>concave</em><em> </em><em>lens</em><em> </em><em>is</em><em> </em><em>thinner</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>cen</em><em>ter</em><em> </em><em>and </em><em>thick</em><em>er</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>edges</em><em> </em><em>while</em><em> </em><em>a</em><em> </em><em>convex </em><em>lens </em><em>is</em><em> </em><em>thicker</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>centre</em><em> </em><em>and</em><em> </em><em>thinner</em><em> </em><em>at</em><em> </em><em>the</em><em> edges</em><em>.</em>
If Earth were 10.0 times farther away from the Sun than it is now, 100 times weaker would the gravitational force between the Sun and Earth.
What is Gravitational Force?
According to Newton's universal law of gravitation, The force of attraction between any two bodies is directly proportional to the product of their masses and is inversely proportional to the square of the distance between them.
What causes gravitational force?
Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body. That's what gives you weight. And if you were on a planet with less mass than Earth, you would weigh less than you do here.
Learn more about gravitational force:
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Answer:
The phase difference between the reflected waves when they meet at the tuning fork is 159.29 rad.
Explanation:
Given that,
Frequency of sound wave = 240 Hz
Distance = 46.0 m
Distance of fork = 14 .0 m
We need to calculate the path difference
Using formula of path difference
Put the value into the formula
We need to calculate the wavelength
Using formula of wavelength
Put the value into the formula
We need to calculate the phase difference
Using formula of the phase difference
Put the value into the formula
Hence, The phase difference between the reflected waves when they meet at the tuning fork is 159.29 rad.
