A sound wave propagates through a region filled with an ideal gas at constant temperature T. It approaches an acoustically perme
able but thermally insulating membrane such that the angle between the wave and the plane of the membrane is 30 degrees. On the other side of the membrane is the same gas at a different temperature T. What is the minimum value of T/T such that no sound passes across the barrier? (You may find it useful to know that the speed of sound in an ideal gas is proportional to VT.) a.1 b.1/2 c.3/4 d.4/3. e.2.
1 answer:
Answer:
The answer is <em>e.2</em>
Explanation:
We should make use of Snell's refractive law. The arriving wave has a certain velocity at T in a medium, then instantly it reaches a medium (same composition) at T' where velocity would either decrease or increase.
When the incidence angle is 30 °, and we want to make the refraction angle 90 ° such that no sound passes through the barrier (this would be named total internal refraction), so we want the second medium to be "faster" than in the first.
<em>The steps are in the image attached:</em>
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Answer:
The magnitude of electric force is
Explanation:
Coulomb's Law:
The force of attraction or repletion is
- directly proportional to the products of charges i.e
- inversely proportional to the square of distance i.e
[ k is proportional constant=9×10⁹N m²/C²]
There are two types of force applied on Q=+2.5 μC=2.5×10⁻⁶ C
Let F₁ force be applied on Q =+2.5 μC by q₁= -5.0 μC = - 5.0×10⁻⁶ C
and F₂ force be applied on Q=+2.5 μC by q₂= 5.0 μC= 5.0×10⁻⁶ C
Since the magnitude of F₁ and F₂ are same. Therefore their y component cancel.
If we draw a line from q₁ to Q .
The it forms a triangle whose base = 4.0 cm and altitude =3.0 cm.
Let hypotenuse = r
Therefore,
we know,
Total force
[ r=5]
N
The magnitude of electric force is