Answer:
The heat input from the combustion phase is 2000 watts.
Explanation:
The energy efficiency of the heat engine (), no unit, is defined by this formula:
(1)
Where:
- Heat input, in watts.
- Power output, in watts.
If we know that and , then the heat input from the combustion phase is:
The heat input from the combustion phase is 2000 watts.
Answer:
(a) 2.39 MPa (b) 3.03 kJ (c) 3.035 kJ
Explanation:
Solution
Recall that:
A 10 gr of air is compressed isentropically
The initial air is at = 27 °C, 110 kPa
After compression air is at = a450 °C
For air, R=287 J/kg.K
cv = 716.5 J/kg.K
y = 1.4
Now,
(a) W efind the pressure on [MPa]
Thus,
T₂/T₁ = (p₂/p₁)^r-1/r
=(450 + 273)/27 + 273) =
=(p₂/110) ^0.4/1.4
p₂ becomes 2390.3 kPa
So, p₂ = 2.39 MPa
(b) For the increase in total internal energy, is given below:
ΔU = mCv (T₂ - T₁)
=(10/100) (716.5) (450 -27)
ΔU =3030 J
ΔU =3.03 kJ
(c) The next step is to find the total work needed in kJ
ΔW = mR ( (T₂ - T₁) / k- 1
(10/100) (287) (450 -27)/1.4 -1
ΔW = 3035 J
Hence, the total work required is = 3.035 kJ
Answer:
Part a: The yield moment is 400 k.in.
Part b: The strain is
Part c: The plastic moment is 600 ksi.
Explanation:
Part a:
As per bending equation
Here
- M is the moment which is to be calculated
- I is the moment of inertia given as
Here
- b is the breath given as 0.75"
- d is the depth which is given as 8"
The yield moment is 400 k.in.
Part b:
The strain is given as
The stress at the station 2" down from the top is estimated by ratio of triangles as
Now the steel has the elastic modulus of E=29000 ksi
So the strain is
Part c:
For a rectangular shape the shape factor is given as 1.5.
Now the plastic moment is given as
The plastic moment is 600 ksi.
Answer:
The material with the higher specific heat capacity would cause a more severe burn.
Explanation:
Quantity of heat (Q) = mass of material (m) × specific heat capacity (C) × temperature difference (∆T)
From the formula above, the relationship between Q and C is direct in which increase in one quantity (C) leads to a corresponding increase in the other quantity (Q)
The material with the higher specific heat capacity would produce more heat, thus cause a more severe burn.
Answer:
a. population, units, sample
Explanation:
In a survey or in a research, population is defined as the total number of people or total number of items in the group that we want to study in a research. It is the entire pool from where a sample is drawn.
An unit is defined as the individual members for which the information or data is collected.
A sample is defined is defined as the group or part of the selection from where the information or data is to be obtained.