Answer:
The answer to the range of a cooling tower is the difference between the temperature of the water going in and the temperature of the water going out of the tower.
Explanation:
Cooling towers are used to cool a stream of water using the air of the environment where it's placed or installed. In theory, the lowest temperature the water can be cooled to would be the wet bulb temperature (temperature of the air going in the cooling tower). The range would be the difference (R=Ti-To) between the temperature of the hot water going in and the cooler water going out.
The heat transfer which is in steady state, the heat transfer rate to the wall is equal to the wall.
<u>Explanation:</u>
- The convection transfer of heat to the wall is
- Here,
is the temperature of solid surface, 
is the temperature of moving fluid stream which is adjacent of solid surface, h is the heat transfer coefficient. - The coefficient of convection heat transfers outer surface contains 3 times to the inner surface which experience smaller drop of temperature for 3 times that compares to inner surface.
- Hence, the temperatures outer surface get close to the surroundings of air temperature.
Answer:
B A and C
Explanation:
Given:
Specimen σ
σ
A +450 -150
B +300 -300
C +500 -200
Solution:
Compute the mean stress
σ
= (σ + σ)/2
σ
= (450 + (-150)) / 2
= (450 - 150) / 2
= 300/2
σ = 150 MPa
σ
= (300 + (-300))/2
= (300 - 300) / 2
= 0/2
σ = 0 MPa
σ
= (500 + (-200))/2
= (500 - 200) / 2
= 300/2
σ = 150 MPa
Compute stress amplitude:
σ
= (σ - σ)/2
σ
= (450 - (-150)) / 2
= (450 + 150) / 2
= 600/2
σ = 300 MPa
σ
= (300- (-300)) / 2
= (300 + 300) / 2
= 600/2
σ = 300 MPa
σ
= (500 - (-200))/2
= (500 + 200) / 2
= 700 / 2
σ = 350 MPa
From the above results it is concluded that the longest fatigue lifetime is of specimen B because it has the minimum mean stress.
Next, the specimen A has the fatigue lifetime which is shorter than B but longer than specimen C.
In the last comes specimen C which has the shortest fatigue lifetime because it has the higher mean stress and highest stress amplitude.
Answer:
Average access time for a hard disk = 11.38 ms
Explanation:
See attached pictures for step by step explanation.
