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:
Explanation:
In this case we will use the Bohr Atomic model.
We have that: 
We can calculate the centripetal force using the coulomb formula that states:
Where K=
and r is the distance.
Now we can say:
The mass of the electron is = 
Kg
The charge magnitud of an electron and proton are= 
Substituting what we have:
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so:
Immediately following the arrival of the stimulus at a skeletal muscle cell, there is a short period called the latent period during which the events of excitation-contraction coupling occur.
This process is a connection between transduction in the sarcolemma and the initiation of muscle contraction. Sarcolemma is nothing but the cell membrane of skeletal muscle.
A single muscle twitch has a latent period, a contraction phase when tension increases and a relaxation phase when tension decreases.
The period of incubation, the interval preceding exposure to a pathogen toxin or radiation, and when effects occur. Muscle contracting, the time between a nerve stimulus and muscle contraction.
To know more about muscles:
brainly.com/question/13753345
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Answer:
A change has occurred in a nucleus
