Answer:
P = 17.28*10⁶ N
Explanation:
Given
L = 250 mm = 0.25 m
a = 0.54 m
b = 0.40 m
E = 95 GPa = 95*10⁹ Pa
σmax = 80 MPa = 80*10⁶ Pa
ΔL = 0.12%*L = 0.0012*0.25 m = 3*10⁻⁴ m
We get A as follows:
A = a*b = (0.54 m)*(0.40 m) = 0.216 m²
then, we apply the formula
ΔL = P*L/(A*E) ⇒ P = ΔL*A*E/L
⇒ P = (3*10⁻⁴ m)*(0.216 m²)*(95*10⁹ Pa)/(0.25 m)
⇒ P = 24624000 N = 24.624*10⁶ N
Now we can use the equation
σ = P/A
⇒ σ = (24624000 N)/(0.216 m²) = 114000000 Pa = 114 MPa > 80 MPa
So σ > σmax we use σmax
⇒ P = σmax*A = (80*10⁶ Pa)*(0.216 m²) = 17280000 N = 17.28*10⁶ N
1) In the first case, the correct answer is
<span>A.Wavelengths measured would match the actual wavelengths emitted.
In fact, the stars are not moving relative to Earth, so there is no shift in the measured wavelength.
2) In this second case, the correct answer is
</span><span>A.Wavelengths measured would be shorter than the actual wavelengths emitted.
</span>in fact, since the stars in this case are moving towards the Earth, then apparent frequency of their emitted light will be larger than the actual frequency, because of the Doppler effect, according to the formula:

where f0 is the actual frequency, f' the apparent frequency, c the speed of light and vs the velocity of the source (the stars) relative to the obsever (Earth). Vs is negative when the source is moving towards the observer, so the apparent frequency f' is larger than the actual frequency f0. But the wavelength is inversely proportional to the frequency, so the apparent wavelength will be shorter than the actual wavelength.
Answer:
"The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by thePauli principle in a particular set of degenerate orbitals" is known as Hund's rule.
Explanation:
Pauli's Exclusion principle states that "two or more electrons can not have the same values of the set of all quantum numbers in an atom or a molecule".
So, the given statement <em>is not</em> Pauli's Exclusion principle.
Hund's rule states that the lowest energy configuration of an atom is that one in which the maximum number of parallel spins of the electrons are present.
The given statement is "The lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by the Pauli principle in a particular set of degenerate orbitals", which is same as the Hund's rule.
Thus, the given statement is Hund' rule.
Heisenberg's uncertainty principle states that the momentum and position of an object can not be measured exactly at the same time.
So, the given statement <em>is not</em> Heisenberg's uncertainty principle.
Aufbau principle tells about the filling of the electrons in subshells of an atom. Therefore, the given statement <em>is not </em>Aufbau principle.
Displacement is zero. That’s because she ended up where she started.