Answer:
58.33 Hz
175 Hz
291.67 Hz
Explanation:
L = Length of tube = 1.5 m
v = Speed of sound in air = 350 m/s
The first resonant frequency is given by

The first resonant frequency is 58.33 Hz
The second resonant frequency is given by

The first resonant frequency is 175 Hz
The third resonant frequency is given by

The first resonant frequency is 291.67 Hz
Answer:
<h3>The answer is 1.92 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula

From the question we have

We have the final answer as
<h3>1.92 g/cm³</h3>
Hope this helps you
QUESTION:
Part A
The induced emf in the loop is measured to be
. What is the magnitude
of the magnetic field that the loop was in?
Part B
For the case of a square loop of side length
being pulled out of the magnetic field with constant speed
(see the figure), what is the rate of change of area
?
Answer:
Part A: 
Part B: 
Explanation:
Part A:
Faraday's law says that the induced voltage is equal to
,
which in our case(because we have only one loop) becomes
,
and since the magnetic field is uniform (not changing),

Now, we know that 
therefore,

which gives us

Part B:
The area of the loop can be written as
,
where
is the instantaneous length of the side along which the loop is moving.
Taking the derivative of both sides we get:
,
and since
we have


where the negative sign indicates that the area is decreasing.
-- The reference level for sound wave intensity is the threshold of human hearing, defined as 10⁻¹² W/m² .
-- This question is talking about a 90dB sound. So its intensity is 10⁻³ W/m² .
-- The question tells us the size of the area that this sound is hitting. So the power absorbed by that area is ...
Power = (intensity) x (area)
Power = (10⁻³ W/m²) x (5 x 10⁻⁵ m²)
Power = (10⁻³ x 5 x 10⁻⁵) W
<em>Power = 5 x 10⁻⁸ Watts</em>
(That's 5 x 10⁻⁸ Joules of energy per second.)