Answer:
4 number answer is correct.
Answer:
See attached image for diagrams and solution
Answer:
a) What is the surface temperature, in °C, after 400 s?
T (0,400 sec) = 800°C
b) Yes, the surface temperature is greater than the ignition temperature of oak (400°C) after 400 s
c) What is the temperature, in °C, 1 mm from the surface after 400 s?
T (1 mm, 400 sec) = 798.35°C
Explanation:
oak initial Temperature = 25°C = 298 K
oak exposed to gas of temp = 800°C = 1073 K
h = 20 W/m².K
From the book, Oak properties are e=545kg/m³ k=0.19w/m.k Cp=2385J/kg.k
Assume: Volume = 1 m³, and from energy balance the heat transfer is an unsteady state.
From energy balance: 
Initial temperature wall = 
Surface temperature = T
Gas exposed temperature = 
Answer:
The glass transition occur when the given temperature gets drop below the temperature of the glass transition for the polymers. During the creases of the long range of the given motion, the polymer start changing from the state of hard into the form of brittle.
The range of the glass transition temperature are between the 0 to -150°C. The basic use of the polymer is basically depend upon the main properties of the polymer.
Answer:
The correct option is;
Materials and Components
Explanation:
The efficiency of fluid power is influenced by the components and the materials used to deliver the power of the fluid as such fluid power control are focused on
1) Advances in fluid power
2) Making use of the advantages
3) Making use of the other externally available technological advantages
4) Giving allowance for disadvantages
Areas of interest in advances in fluid power are;
a. Computer optimized flow
b. The use of new and improved materials/coatings
c. The use of components that save energy, such as intelligent supply pressure adapting systems
