The question is incomplete. The complete question is :
Two loudspeakers are placed 1.8 m apart. They play tones of equal frequency. If you stand 3.0 m in front of the speakers, and exactly between them, you hear a minimum of intensity. As you walk parallel to the plane of the speakers, staying 3.0 m away, the sound intensity increases until reaching a maximum when you are directly in front of one of the speakers. The speed of sound in the room is 340 m/s.
What is the frequency of the sound?
Solution :
Given :
The distance between the two loud speakers, 
The speaker are in phase and so the path difference is zero constructive interference occurs.
At the point 
, the speakers are out of phase and so the path difference is 
Therefore,
Thus the frequency is :
Hz
Wavelength can be calculated using the following formula: wavelength = wave velocity/frequency. Wavelength usually is expressed in units of meters.
Answer:
Explanation:
Given that,
The work function for silver is 4.73 eV.
We need to find the value of the work function from electron volts to joules.
We know that,
For 4.73 eV,
So, the work function for silver is 
.
Answer:
Difference in Twin's Ages = 12.68 years
Explanation:
Using special theory of relativity's time dilation phenomenon, we first find the time that is passed on earth during Lou's trip.
t = t₀/[√(1 - v²/c²)]
where,
t = time measured by the person in relative motion = 1 year
t₀ = time measured by the person at rest = ?
v = speed of relative motion = 0.96 c
c = speed of light
Therefore,
1 year = t₀/[√(1 - 0.96² c²/c²)]
1 year = t₀/[√(1 - 0.9216)]
(1 year)(0.28 year) = t₀
t₀ = 0.28 year
Let,
y = Sue's age
x = Lou's age
so,
x - y = 13.4 years
but, after this trip Lou has aged 1 year, and on earth only 0.28 years passed so, Sue has aged only 0.28 years. Therefore,
x = x + 1
y = y + 0.28
Therefore,
(x + 1 year) - (y + 0.28 year) = 13.4 years
x - y = 13.4 years - 0.72 year
x - y = 12.68 years
<u>Difference in Twin's Ages = 12.68 years</u>
Answer:
Fm is the net force down on the metal in air
Fm / 2 is the net force down on the metal in liquid
Fl is the buoyant force on the metal due to liquid
Fm - Fl = Fm / 2 equating upward and downward forces
Fm / 2 = Fl
The specific gravity of the metal is twice that of the liquid
Note: F = M g = ρ V g since ρ = M / V
