~Hello there!
Your questions: The rare Earth elements include ___________________.
Your answer: There are many Earth elements but some of the rare elements are the following as mentioned:
1) Gadolinium
2) Holmium
3) Yttrium
4) Promethium
5) Samarium.
Note: These are some of the rare Earth elements, there are MANY rare elements that are found in Earth.
Any questions ^?
Happy Studying!
We will first determine using the given if an aircraft component will fracture with a given stress level (260 MPa), maximum internal crack length (6.0 mm) and fracture toughness (40 MPa m ), given that fracture occurs for the same component using the same alloy for another stress level and internal crack length. First, it is necessary to solve for the parameter Y, using Equation 8.5, for the conditions under which fracture occurred (i.e., σ = 300 MPa and 2 a = 4.0 mm). Therefore,
Y = K(Ic)/ sqrt(π a) = 40 MPa( m ) / (300 MPa) sqrt(( π ) ((4 × 10-3 m)/2)) = 1.68
We will now solve for the product Y σ π a for the other set of conditions, so as to ascertain whether or not this value is greater than the K(Ic) for the alloy. Thus,
Y sqrt(π a) = (1.68)(260 MPa) sqrt (( π )[(6 × 10^-3 m)/ 2])
= 42.4 MPa sqrt (m) (39 ksi in. )
Therefore, fracture will occur since this value ( 42.4 MPa sqrt(m)) is greater than the K(Ic) of the material, 40 MPa sqrt(m).
Answer:
Stretch and moving away from us, with more distant ones moving faster
Explanation:
Astronomers observed that the entire universe is getting bigger because distant galaxies appears to be moving away from us
Explanation:
It is given that,
Wavelength, 
Wavelength, 
We need to find the frequencies from corresponding wavelengths. The frequency of the light is given by :
c is the speed of light
Frequency 1,
Frequency 2,
Hence, this is the required solution.
