Answer:
Farmers who use conventional tillage use compost more than other farmers.
Explanation:
Convectional tillage is good to the environment because it attains the following;
- It increases porosity of the soil
- It loosens the soil thus allowing proper root growth and air exchange
- It is an effective way to incorporate manure and break sod fields
- Tilled soils warm faster in spring
Answer:
M_c = 61.6 Nm
Explanation:
Given:
F_a = 2.5 KN
Find:
Determine the moment of this force about C for the two casesshown.
Solution:
- Draw horizontal and vertical vectors at point A.
- Take moments about point C as follows:
M_c = F_a*( 42 / 150 ) *88
M_c = 2.5*( 42 / 150 ) *88
M_c = 61.6 Nm
- We see that the vertical component of force at point A passes through C.
Hence, its moment about C is zero.
Answer:
≅ 111 KN
Explanation:
Given that;
A medium-sized jet has a 3.8-mm-diameter i.e diameter (d) = 3.8
mass = 85,000 kg
drag co-efficient (C) = 0.37
(velocity (v)= 230 m/s
density (ρ) = 1.0 kg/m³
To calculate the thrust; we need to determine the relation of the drag force; which is given as:
=
× CρAv²
where;
ρ = density of air wind.
C = drag co-efficient
A = Area of the jet
v = velocity of the jet
From the question, we can deduce that the jet is in motion with a constant speed; as such: the net force acting on the jet in the air = 0
SO, 
We can as well say:

We can now replace
in the above equation.
Therefore,
=
× CρAv²
The A which stands as the area of the jet is given by the formula:

We can now have a new equation after substituting our A into the previous equation as:
=
× Cρ 
Substituting our data from above; we have:
=
× 
= 
= 110,990N
in N (newton) to KN (kilo-newton) will be:
= 
= 110.990 KN
≅ 111 KN
In conclusion, the jet engine needed to provide 111 KN thrust in order to cruise at 230 m/s at an altitude where the air density is 1.0 kg/m³.
Answer:Counter,
0.799,
1.921
Explanation:
Given data




Since outlet temperature of cold liquid is greater than hot fluid outlet temperature therefore it is counter flow heat exchanger
Equating Heat exchange
![m_hc_{ph}\left [ T_{h_i}-T_{h_o}\right ]=m_cc_{pc}\left [ T_{c_o}-T_{c_i}\right ]](https://tex.z-dn.net/?f=m_hc_%7Bph%7D%5Cleft%20%5B%20T_%7Bh_i%7D-T_%7Bh_o%7D%5Cright%20%5D%3Dm_cc_%7Bpc%7D%5Cleft%20%5B%20T_%7Bc_o%7D-T_%7Bc_i%7D%5Cright%20%5D)
=
we can see that heat capacity of hot fluid is minimum
Also from energy balance

=


NTU=1.921




