Answer:
i) 25.04 W/m^2 .k
ii) 23.82 minutes = 1429.2 secs
Explanation:
Given data:
Diameter of steel ball = 15 cm
uniform temperature = 350°C
p = 8055 kg/m^3
Cp = 480 J/kg.k
surface temp of ball drops to 250°C
average surface temperature = ( 350 + 250 ) / 2 = 300°C
<u>i) Determine the average convection heat transfer coefficient during the cooling process</u>
<em>Note : Obtain the properties of air at 1 atm at average film temp of 30°C from the table " properties of air " contained in your textbook</em>
average convection heat transfer coefficient = 25.04 W/m^2 .k
<u>ii) Determine how long this process has taken </u>
Time taken by the process = 23.82 minutes = 1429.2 seconds
Δt = Qtotal / Qavg = 683232 / 477.92 = 1429.59 secs
attached below is the detailed solution of the given question
Answer:
12
Explanation:
19-7 lol this is to easy im in middle school
Complete Question:
A metal plate of 400 mm in length, 200mm in width and 30 mm in depth is to be machined by orthogonal cutting using a tool of width 5mm and a depth of cut of 0.5 mm. Estimate the minimum time required to reduce the depth of the plate by 20 mm if the tool moves at 400 mm per second.
Answer:
26 mins 40 secs
Explanation:
Reduction in depth, Δd = 20 mm
Depth of cut, 
Number of passes necessary for this reduction, 
n = 20/0.5
n = 40 passes
Tool width, w = 5 mm
Width of metal plate, W = 200 mm
For a reduction in the depth per pass, tool will travel W/w = 200/5 = 40 times
Speed of tool, v = 100 mm/s
minimum time required to reduce the depth of the plate by 20 mm:
number of passes * Time/pass
n * Time/pass
40 * 40
1600 = 26 mins 40 secs
Based on the calculations, the absolute pressure in the pipe is equal to 90,670.4 N/m².
<h3>How to calculate the absolute pressure?</h3>
Mathematically, absolute pressure can be calculated by using this formula:
<u>Scientific data:</u>
Atmospheric pressure (Patm) = 1 bar = 1 × 10⁵ N/m²
Head (h) = -70mmhg = -0.07 m hg
Acceleration due to gravity = 9.8 m/s²
Density of mercury = 13,600 kg/m³.
Next, we would determine the gauge pressure:
Now, we can calculate the absolute pressure:
Absolute pressure = 90,670.4 N/m².
Read more on absolute pressure here: brainly.com/question/10013312
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Answer: all you need to to is go to help me with this question.cm
Explanation:
