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
Well the heat that is needed to raise the temperature of 10g of water by 17oC is 7
Answer:
L = 40 cm
Explanation:
A microscope is an optical instrument built by two lenses in such a way that the image of the first is formed within the distance of the other (eyepiece), so that the latter creates an enlarged virtual image of the object, for which the magnification of the microscope is the same to the multiplication of the magnification of each lens
M = - L / f₀ (25 cm /
)
where fo and fe are the focal lengths of the objective and eyepiece, 25 cm is the near vision distance and L is the length of the microscope
L = - M f_{o} f_{e} / 25
let's calculate
L = - (-100) 2 5/25
L = 40 cm
Velocity = The speed and direction that an object is moving at
Let's call a the acceleration of the system. The problem says that the block m3 is static, so the acceleration is zero: a=0.
Calling
the tension of the string between m1 and m3, and
the tension of the string between m2 and m3, the problem can be solved by writing the following system of equations:
However, we know that a=0 and the problem asks only for
, so we just need to solve the first equation:
and so
