Answer:
The convective coefficient is 37.3 W/m²K.
Explanation:
Use Newton’s law of cooling to determine the heat transfer coefficient. Assume there is no heat transfer from the ends of electric resistor. Heat is transferred from the resistor curved surface.
Step1
Given:
Diameter of the resistor is 2 cm.
Length of the resistor is 16 cm.
Current is 5 amp.
Voltage is 6 volts.
Resistor temperature is 100°C.
Room air temperature is 20°C.
Step2
Electric power from the resistor is transferred to heat and this heat is transferred to the environment by means of convection.
Power of resistor is calculated as follows:
P=VI
P= 30 watts.
Step3
Newton’s law of cooling is expressed as follows:
Here, h is the convection heat coefficient and 
is the exposed surface area of the resistor.
Substitute the values as follows:
h = 37.3 W/m²K.
Thus, the convective coefficient is 37.3 W/m²K.
Answer:
<em>The plumbing is designed to reduce the impact of pressure forces due to the height of skyscrapers. This is achieves by narrowing down the pipe down to the basement, using pipes with thicker walls down the basement, and allowing vents; to prevent clogging of the pipes.</em>
<em></em>
Explanation:
<em>Pressure increases with depth and density</em>. In skyscrapers, a huge problem arises due to the very tall height of most skyscrapers. Also, sewage slug coming down has an increased density when compared to that of water, and these two factors can't be manipulated. The only option is to manipulate the pipe design. <em>Pipes in skyscrapers are narrowed down with height, to reduce accumulation at the bottom basement before going to the sewage tank. Standard vents are provided along the pipes, to prevent clogging of the pipes, and pipes with thicker walls are used as you go down the basement of the skyscraper, to withstand the pressure of the sewage coming down the pipes.</em>
Answer:
To divide the ultimate (or maximum) stress by the typical (or working) stress.
Explanation:
Hopes this helps :)
