Answer:
Δr=20.45 %
Explanation:
Given that
Rake angle α = 15°
coefficient of friction ,μ = 0.15
The friction angle β
tanβ = μ
tanβ = 0.15
β=8.83°
2φ + β - α = 90°
φ=Shear angle
2φ + 8.833° - 15° = 90°
φ = 48.08°
Chip thickness r given as
r=0.88
New coefficient of friction ,μ' = 0.3
tanβ' = μ'
tanβ' = 0.3
β'=16.69°
2φ' + β' - α = 90°
φ'=Shear angle
2φ' + 16.69° - 25° = 90°
φ' = 49.15°
Chip thickness r' given as
r'=0.70
Percentage change
Δr=20.45 %
The temperature drop of air if air is assumed to be an ideal gas for which C_p = ⁷/₂R is; Δt = 1546 K
We are given;
Final velocity; v₂ = 300 m/s
C_p = ⁷/₂R
At constant pressure, the change in enthalpy is;
Δh = C_p × Δt
Now, from first law of thermodynamics;
h₂ + (v₂²/2) = h₁ + (v₁²/2)
We are told initial velocity is negligible and as such v₁ = 0 m/s
Thus;
h₂ + (v₂²/2) = h₁ + 0
(h₁ - h₂) = (v₂²/2)
Thus; Δh = v₂²/2
Finally;
C_p × Δt = v₂²/2
Δt = v₂²/2/(C_p)
Δt = (300²/2)/(⁷/₂R)
where R is ideal gas constant = 8.314 Kj/kg.mol
Thus;
Δt = (300²/2)/(⁷/₂ × 8.314)
Δt = 1546 K
Read more at; brainly.com/question/24188841
Answer:
ΔH+U²/2=0
and
ΔH=×ΔT
∴to get the temperature drop of air, you make ΔT subject of the formula
ΔT=-U²/2Cp
=-300²/2××8.314
∴ΔT=-1546K
Explanation:
Answer:
Too many question marks
Explanation:
Answer:
The problem is that the pumps would consume more energy than the generators would produce.
Explanation:
Water has a potential energy associated with the height it is at. The higher it is, the higher the potential energy. When water flows down into the turbines that energy is converted to kinetic energy and then into electricity.
A pump uses electricity to add energy to the water to send it to a higher potential energy state.
Ideally no net energy woul be hgenerate or lost, because the generators would release the potential energy and pumps would store it again in the water. However the systems are not ideal, everything has an efficiency and losses. The losses would accumulate and the generator would be generating less energy than the pumps consume, so that system wastes energy.
What should be done is closing the floodgates to keep the water up in the dam at night producing only the power that is needed and releasing more water during the day.
Answer:
C)185,500 KJ
Explanation:
Given that
Latent heat fusion = 333.23 KJ/kg
Latent heat vaporisation = 333.23 KJ/kg
Mass of ice = 100 kg
Mass of water = 40 kg
Mass of vapor=60 kg
Ice at 0°C ,first it will take latent heat of vaporisation and remain at constant temperature 0°C and it will convert in to water.After this water which at 0°C will take sensible heat and gets heat up to 100°C.After that at 100°C vapor will take heat as heat of vaporisation .
Sensible heat for water Q
For water
Q=4.178 x 40 x 100 KJ
Q=16,712 KJ
So total heat
Total heat =100 x 333.23+16,712 + 60 x 2257 KJ
Total heat =185,455 KJ
Approx Total heat = 185,500 KJ
So the answer C is correct.