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4 years ago

Why does an aeroplane smoke in the air

1 answer:

3 0

The reason airplanes leave a white smoke trail in their wake is because their exhaust gases contain moisture that condenses at high altitudes.

Hope this helps!

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When _____ ,the lithium ions are removed from the_____ and added into the _____

bezimeni [28]

Answer:

b. Discharging; anode; cathode

Explanation:

When discharging , it means the battery is producing a flow electric current, the lithium ions are released from the anode to the cathode which generates the flow of electrons from one side to another. When charging Lithium ions are released by the cathode and received by the anode.

8 0

3 years ago

Consider a steam turbine, with inflow at 500oC and 7.9 MPa. The machine has a total-to-static efficiency ofηts=0.91, and the pre

sergiy2304 [10]

Answer: $\dot m_{in} = 23.942 \frac{kg}{s}$ , $\dot H_{out} = 39632.62 kW$

Explanation:

Since there is no information related to volume flow to and from turbine, let is assume that volume flow at inlet equals to $\dot V = 1 \frac{m^{3}}{s}$ . Turbine is a steady-flow system modelled by using Principle of Mass Conservation and First Law of Thermodynamics:

Principle of Mass Conservation

$\dot m_{in} - \dot m_{out} = 0$

First Law of Thermodynamics

$- \dot W_{out} + \eta\cdot (\dot m_{in} \dot h_{in} - \dot m_{out} \dot h_{out}) = 0$

This 2 x 2 System can be reduced into one equation as follows:

$-\dot W_{out} + \eta \cdot \dot m \cdot ( h_{in}- h_{out})=0$

The water goes to the turbine as Superheated steam and goes out as saturated vapor or a liquid-vapor mix. Specific volume and specific enthalpy at inflow are required to determine specific enthalpy at outflow and mass flow rate, respectively. Property tables are a practical form to get information:

Inflow (Superheated Steam)

$\nu_{in} = 0.041767 \frac{m^{3}}{kg} \\h_{in} = 3399.5 \frac{kJ}{kg}$

The mass flow rate can be calculated by using this expression:

$\dot m_{in} =\frac{\dot V_{in}}{\nu_{in}}$

$\dot m_{in} = 23.942 \frac{kg}{s}$

Afterwards, the specific enthalpy at outflow is determined by isolating it from energy balance:

$h_{out} =h_{in}-\frac{\dot W_{out}}{\eta \cdot \dot m}$

$h_{out} = 1655.36 \frac{kJ}{kg}$

The enthalpy rate at outflow is:

$\dot H_{out} = \dot m \cdot h_{out}$

$\dot H_{out} = 39632.62 kW$

3 0

3 years ago

An insulated piston–cylinder device initially contains 1 m3 of air at 120 kPa and 17°C. Air is now heated for 15 min by a 200-W

irakobra [83]

Answer:

∆S1 = 0.5166kJ/K

∆S2 = 0.51826kJ/K

Explanation:

Check attachment for solution

4 0

3 years ago

Based on the concept that it is better to prevent falls happening in the first place, which of the following safety methods meet

alekssr [168]

Answer:fall arrest harness

Explanation:cuz it’s just right

7 0

3 years ago

You have a 12-inch PVC water main that is 850 feet long flowing at 5.6 cfs. Point A is at an elevation of 750 ft. Point B is at

alex41 [277]

Known :

D = 12 in = 1 ft

L = 850 ft

Q = 5.6 cfs

hA = 750 ft

hB = 765 ft

PA = 85 psi = 12240 lb/ft²

Solution :

A = πD² / 4 = π(1²) / 4

A = 0.785 ft²

<u>Velocity of water :</u>

U = Q / A = 5.6 / 0.785

U = 7.134 ft/s

<u>Friction loss due to pipe length :</u>

Re = UD / v = (7.134)(1) / (0.511 × 10^(-5))

Re = 1.4 × 10⁶

(From Moody Chart, We Get f = 0.015)

hf = f(L / d)(U² / 2g) = 0.015(850 / 1)((7.134²) / 2(32.2))

hf = 10 ft

PA + γhA = PB + γhB + γhf

PB = PA + γ(hA - hB - hf)

PB = 12240 + (62.4)(750 - 765 - 10)

PB = 10680 lb/ft²

PB = 74.167 psi

8 0

3 years ago

Why does an aeroplane smoke in the air​

Why does an aeroplane smoke in the air