As long as the equation in question can be expressed as the sum of the three equations with known enthalpy change, its 
can be determined with the Hess's Law. The key is to find the appropriate coefficient for each of the given equations.
Let the three equations with given be denoted as (1), (2), (3), and the last equation (4). Let 
, 
, and 
be letters such that 
. This relationship shall hold for all chemicals involved.
There are three unknowns; it would thus take at least three equations to find their values. Species present on both sides of the equation would cancel out. Thus, let coefficients on the reactant side be positive and those on the product side be negative, such that duplicates would cancel out arithmetically. For instance, 
shall resemble the number of 
left on the product side when the second equation is directly added to the third. Similarly
Thus
and
Verify this conclusion against a fourth species involved- 
for instance. Nitrogen isn't present in the net equation. The sum of its coefficient shall, therefore, be zero.
Apply the Hess's Law based on the coefficients to find the enthalpy change of the last equation.
Answer:
1632 Hz
Explanation:
We'll begin by calculating the frequency of each wave. This can be obtained as follow:
1st wave:
Velocity (v) = 340 m/s.
Wavelength 1 (λ₁) = 5 m
Frequency 1 (f₁) =?
v = λ₁f₁
340 = 5 × f₁
Divide both side by 5
f₁ = 340 / 5
f₁ = 68 Hz
2nd wave:
Velocity (v) = 340 m/s.
Wavelength 2 (λ₂) = 0.2 m
Frequency 2 (f₂) =?
v = λ₂f₂
340 = 0.2 × f₂
Divide both side by 0.2
f₂ = 340 / 0.2
f₂ = 1700 Hz
Finally, we shall determine the difference in the frequency of both waves.
This can be obtained as follow:
Frequency 1 (f₁) = 68 Hz
Frequency 2 (f₂) = 1700 Hz
Difference =?
Difference = f₂ – f₁
Difference = 1700 – 68
Difference = 1632 Hz
F2 equals 10 N and F4 equals 2 N
Explanation:
i will answer your question as possible as soon
:
:
: