To develop this problem it is necessary to apply the concept of Frequency based on speed and wavelength.
According to the definition the frequency can be expressed as

Where,
v = Velocity
Wavelength
Our value are given by,
v = 345m/s

Replacing


Therefore the frequency of the tuning fork is 547.61Hz
Explanation:
Let magnitude of the two forces be x and y.
Resultant at right angle R1= √15N) and at
60 degrees be R2= √18N.
Now, R1 = √(x² + y²) = √15,
R2= √(x² + y² +2xycos50) = √18.
So x² + y² = 15,
and x² + y² + 1.29xy = 18,
therefore 1.29xy = 3,
y = 3/1.29x.
y = 2.33/x
Now, x2 + (2.33/x)2 = 15,
x² + 5.45/x² = 15
multiply through by x²
x⁴ + 5.45 = 15x²
x⁴ - 15x2 + 5.45 = 0
Now find the roots of the equation, and later y. The two values of x will correspond to the
magnitudes of the two vectors.
Good luck
Thermal equilibrium is a state in which all parts of a system are at the same temperature
Answer:
Temperature, T = 1542.10 K
Explanation:
It is given that,
The black body radiation emitted from a furnace peaks at a wavelength of, 
We need to find the temperature inside the furnace. The relationship between the temperature and the wavelength is given by Wein's law i.e.

or

b = Wein's displacement constant



T = 1542.10 K
So, the temperature inside the furnace is 1542.10 K. Hence, this is the required solution.
The end or finish of an event or process.