Given Information:
Inlet Temperature of hot air= Th₁ = 450K
Exit Temperature of hot air = Th₂ = 350K
Inlet Temperature of cold air = Tc₁ = 300K
Volume flow rate of hot air = vh = 0.02 m³/s
Volume flow rate of cold air = vc = 1 m³/s
Required Information:
Exit Temperature of cold air= Tc₂ = ?
Answer:
Exit Temperature of cold air = Tc₂ = 302 °C
Explanation:
In a heat exchanger, the cold air absorbs heat that is lost by the hot air,
Heat absorbed by cold air = Heat lost by hot air
![m_{c}\cdot c_{p}(T_{c2} -T_{c1} ) = m_{h}\cdot c_{p}(T_{h1} -T_{h2})\\m_{c}(T_{c2} -T_{c1} ) = m_{h}(T_{h1} -T_{h2})\\\rho\dot{v_{c}}(T_{c2} -T_{c1} ) =\rho\dot{v_{h}} (T_{h1} -T_{h2})\\\dot{v_{c}}(T_{c2} -T_{c1} ) =\dot{v_{h}} (T_{h1} -T_{h2})\\1 \cdot(T_{c2} -300 ) =0.02\cdot (450 -350)\\(T_{c2} -300 ) =0.02\cdot (100)\\(T_{c2} -300 ) =2\\T_{c2} =2 + 300 \\T_{c2} = 302](https://tex.z-dn.net/?f=m_%7Bc%7D%5Ccdot%20c_%7Bp%7D%28T_%7Bc2%7D%20-T_%7Bc1%7D%20%29%20%3D%20m_%7Bh%7D%5Ccdot%20c_%7Bp%7D%28T_%7Bh1%7D%20-T_%7Bh2%7D%29%5C%5Cm_%7Bc%7D%28T_%7Bc2%7D%20-T_%7Bc1%7D%20%29%20%3D%20m_%7Bh%7D%28T_%7Bh1%7D%20-T_%7Bh2%7D%29%5C%5C%5Crho%5Cdot%7Bv_%7Bc%7D%7D%28T_%7Bc2%7D%20-T_%7Bc1%7D%20%29%20%3D%5Crho%5Cdot%7Bv_%7Bh%7D%7D%20%28T_%7Bh1%7D%20-T_%7Bh2%7D%29%5C%5C%5Cdot%7Bv_%7Bc%7D%7D%28T_%7Bc2%7D%20-T_%7Bc1%7D%20%29%20%3D%5Cdot%7Bv_%7Bh%7D%7D%20%28T_%7Bh1%7D%20-T_%7Bh2%7D%29%5C%5C1%20%5Ccdot%28T_%7Bc2%7D%20-300%20%29%20%3D0.02%5Ccdot%20%28450%20-350%29%5C%5C%28T_%7Bc2%7D%20-300%20%29%20%3D0.02%5Ccdot%20%28100%29%5C%5C%28T_%7Bc2%7D%20-300%20%29%20%3D2%5C%5CT_%7Bc2%7D%20%20%3D2%20%2B%20300%20%5C%5CT_%7Bc2%7D%20%20%3D%20302)
Therefore, the exit temperature of the cold air is 302 °C or 575K
Note:
m = ρv
Where ρ is density of air and v is the volume flow rate and m is the mass flow rate.
cp is the specific heat capacity of air.
Igneous rocks are rocks that form through the cooling and solidification of magma or lava.
Answer:
a) the force goes down, b) The electric force is out of the screen
c) the force is zero
Explanation:
To determine the direction of a magnetic force we use the right hand rule. For a positive charge, the thumb is in the direction of speed, the fingers extended in the direction of the magnetic field, and the palm points in the direction of force. Let's apply this to our case
a) thumb to the right
Fingers spread out
And the force goes down
b) the electric force in the direction of the electric field if the charge is positive
Positive charge
Electric field out of the screen
The electric force is out of the screen
c) charge moving out screen
Magnetic field entered on the screen
Since they are parallel, therefore the force is zero
Explanation:
may I ask what it is on because I might be able to help out