Answer:
Recall the formula for the maximum stress, σₐ = 2σ₀ *√ (α/ρₓ)
where
σ₀ = tensile stress = 140 MPa = 1.40x 10⁸Pa
α = crack length = 3.8 × 10–2 mm = 3.8 x 10⁻⁵m
ρₓ = radius of curvature = 1.9 × 10⁻⁴mm = 1.9 × 10⁻⁷m
Substituting these values into the formula, we can calculate the max stress as
====== 2 x 1.40x 10⁸ x √(3.8 x 10⁻⁵/1.9 × 10⁻⁷)
σₐ = 24.4MPa
Answer: = 1.47kJ/K
Explanation: <u>Entropy</u> is the measure of a system's molecular disorder, i.e, the unuseful work a system does.
The nitrogen gas in the insulated tank can be described as an ideal gas, so it can be used the related formulas.
For the entropy, the ratio of initial and final temperatures is needed and as volume is constant, we use:
<u>Specific</u> <u>Heat</u> is the quantity of heat required to increase the temperature 1 degree of a unit mass of a substance. Specific heat of nitrogen at constant volume is 0.743kJ/kg.K
The change in entropy is calculated by
For the nitrogen insulated in a rigid tank:
Substituing:
1.47
The entropy change of nitrogen in an insulated rigid tank is 1.47kJ/K
Answer:
Option C = Only 1 path for current to flow.