Answer:
temperature T2 = 826.9°C
= -1142.7 kJ/kg
Explanation:
given data
initial state temperature = 120°C
final state pressure p1 = 1 bar
pressure p2 = 100 bar
solution
we use here super heated water table A6 that is
specific internal energy u1 = 2537.3 kJ/kg
specific entropy s1 = 7.4668 kJ/kg.K
and
here specific entropy stage 1 = stage 2
so for specific entropy and pressure 100 bar
specific internal energy u2 = 3680 kJ/kg
and temperature T2 = 826.9°C
so here now we get specific work of steam is
ΔU = -W ...........1
m ( u1 - u2) = W
= u1 - u2
= 2537.3 - 3680
= -1142.7 kJ/kg
Answer:
Correct option a) True.
Explanation:
It is true since the Vickers hardness value refers to the force applied in a 136 ° diamond tip penetrator divided by the surface of the groove produced in the material, the lower the impression made on this greater the value will be end of the Vickers measurement and greater its hardness.
The equation to determine the Vickers hardness value will be:
Hv= ((1.854 × P)/(d²)) (kg/mm²)
Therefore a value of 220 Vickers refers to a harder material than another value of 180 Vickers.
Answer:
The 5/16 – 24 UNF is stronger because it has more tensile load capacity.
Tensile load capacity for M8 -1.25 = 5670 lb
Tensile load capacity for M8 -1 = 6067 lb
Explanation:
For 5/16 - 18 UNC thread:
D = 0.3125
n = 18
Therefore the tensile load capacity is = 100000 X (0.7854 X (0.3125 - 0.9743/ 18) ^2
= 5243 lb.
Similarly for 5/16 - 24 UNF , only the n value changes to 24
we get the tensile load capacity = 5806.6 lb
Hence the 5/16 – 24 UNF is stronger because it has more tensile load capacity.
For metric Bolts:
We have to consider all values in SI units
Strength = 689 MPa
We get for M8 -1.25:
Tensile load capacity as = 689 X 36.6 = 25223 N = 5670 lb
For M8 -1:
Tensile load capacity as = 689 X 39.167 = 26986 N = 6067lb
Answer:
165 mm
Explanation:
The mass on the piston will apply a pressure on the oil. This is:
p = f / A
The force is the weight of the mass
f = m * a
Where a in the acceleration of gravity
A is the area of the piston
A = π/4 * D1^2
Then:
p = m * a / (π/4 * D1^2)
The height the oil will raise is the heignt of a colum that would create that same pressure at its base:
p = f / A
The weight of the column is:
f = m * a
The mass of the column is its volume multiplied by its specific gravity
m = V * S
The volume is the base are by the height
V = A * h
Then:
p = A * h * S * a / A
We cancel the areas:
p = h * S * a
Now we equate the pressures form the piston and the pil column:
m * a / (π/4 * D1^2) = h * S * a
We simplify the acceleration of gravity
m / (π/4 * D1^2) = h * S
Rearranging:
h = m / (π/4 * D1^2 * S)
Now, h is the heigth above the interface between the piston and the oil, this is at h1 = 42 mm. The total height is
h2 = h + h1
h2 = h1 + m / (π/4 * D1^2 * S)
h2 = 0.042 + 10 / (π/4 * 0.14^2 * 0.8) = 0.165 m = 165 mm
