Answer: the thermal conductivity of the sample is 22.4 W/m . °C
Explanation:
We already know that the thermal conductivity of a material is to be determined by ensuring one-dimensional heat conduction, and by measuring temperatures when steady operating conditions are reached.
ASSUMPTIONS
1. Steady operating conditions exist since the temperature readings do not change with time.
2. Heat losses through lateral surfaces are well insulated, and thus the entire heat generated by the heater is conducted through the samples.
3. The apparatus possess thermal symmetry
ANALYSIS
The electrical power consumed by resistance heater and converted to heat is:
Wₐ = V<em>I</em> = ( 110 V ) ( 0.4 A ) = 44 W
Q = 1/2Wₐ = 1/2 ( 44 A )
Now since only half of the heat generated flows through each samples because of symmetry. Reading the same temperature difference across the same distance in each sample also confirms that the apparatus possess thermal symmetry. The heat transfer area is the area normal to the direction of heat transfer. which is the cross- sectional area of the cylinder in this case; so
A = 1/4πD² = 1/3 × π × ( 0.05 m )² = 0.001963 m²
Now Note that, the temperature drops by 15 degree Celsius within 3 cm in the direction of heat flow, the thermal conductivity of the sample will be
Q = kA ( ΔT/L ) → k = QL / AΔT
k = ( 22 W × 0.03 m ) / (0.001963 m² × 15°C )
k = 22.4 W/m . °C
Answer:
<em>There are few effective Human Computer Interaction (HCI) standards because for one, standards are more suitable for hardware than software because they are relatively unstable. ... Some software product standards have been in place long before any formal standard documents were published.</em>
If the diameter of the bar is 0.490 at this load, determine I. the engineering stress and strain, and [2] II. the true stress and strain is 1561. 84 MPa.
<h3>What is strain?</h3>
Strain is a unitless degree of ways a great deal an item receives larger or smaller from an implemented load. Normal stress happens while the elongation of an item is in reaction to an everyday pressure (i.e. perpendicular to a surface), and is denoted via way of means of the Greek letter epsilon.
- L = 20 cm d x 1 = 0.21 cm
- dx 2 = 0.25 cmF=5500 a) σ= F/A1= 5000/(π/4x(0.0025)^2)= 1018.5916 MPa lateral stress= Ad/d1= (0.0021-0.0025)/0.0025 = - 0.1 longitudinal stress (ɛ_l)= -lateral stress/v = -(-0.16)/0.3
- (assuming a poisson's ration of 0.3) ε_l=0.16/0.3 = 0.5333
- b) σ_true= σ(1+ ɛ_I)= 1018.5916(1+0.5333
- = 1561.84 MPa.
Read more about the diameter :
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Explanation:
Step1
Strength is the maximum stress induces in the material under applied load condition. More the strength more will be ability to sustain load. Strength can be measured from tensile test. It has same unit as stress. Generally ductile material has more strength as compare to brittle material.
Step2
Hardness is the resistance to scratch on the material under given load condition. More the hardness more will be the resistance towards scratching of material. Hardness can be measured by Rockwell or Birnell hardness test. This property of metal is opposite to the strength.
Step3
Toughness is the ability to absorb energy under given loading condition up to its fracture point. It is a type of strain energy that is stored in the metal. Generally ductile metal has more toughness as compare to brittle.
Test element is used to apply test execution settings for the main business flow excluding Login and Log out is "Transaction controller"
<u>Explanation:</u>
Transaction controllers are a technoscientifically kind of controllers that produce an additional sample that measures the overall time is taken or response time to perform its nested samplers.
The Controller has two checkboxes,those are
1.Generate Parent Samples
2. Include term of the timer and pre-post processors in the produced sample - It is the time which involves all processing samples within the Transaction controller, not just the HTTP samples. In Case one sample is lost or crashed then the entire Transaction Controller will fail. In case anyone sample assertion is failed then the complete Transaction Controller will fail.
