Answer:
Option ‘a’ is the cheapest for this house.
Explanation:
Cheapest method of heating must have least cost per kj of energy. So, convert all the energy in the same unit (say kj) and take select the cheapest method to heat the house.
Given:
Three methods are given to heat a particular house are as follows:
Method (a)
Through Gas, this gives energy of amount $1.33/therm.
Method (b)
Through electric resistance, this gives energy of amount $0.12/KWh.
Method (c)
Through oil, this gives energy of amount $2.30/gallon.
Calculation:
Step1
Change therm to kj in method ‘a’ as follows:

$/kj.
Step2
Change kWh to kj in method ‘b’ as follows:

$/kj.
Step3
Change kWh to kj in method ‘c’ as follows:

$/kj.
Thus, the method ‘a’ has least cost as compare to method b and c.
So, option ‘a’ is the cheapest for this house.
I believe it’s c because you don’t want your gas to run real low, so I think it’s best to do it when your fuel.
A. I believe, lmk if I’m right
Answer:
5.6 mm
Explanation:
Given that:
A cylindrical tank is required to contain a:
Gage Pressure P = 560 kPa
Allowable normal stress
= 150 MPa = 150000 Kpa.
The inner diameter of the tank = 3 m
In a closed cylinder there exist both the circumferential stress and the longitudinal stress.
Circumferential stress 
Making thickness t the subject; we have


t = 0.0056 m
t = 5.6 mm
For longitudinal stress.



t = 0.0028 mm
t = 2.8 mm
From the above circumferential stress and longitudinal stress; the stress with the higher value will be considered ; which is circumferential stress and it's minimum value with the maximum thickness = 5.6 mm
Answer:
6.6 kilo volts = 6.6 k volts
Explanation:
A prefix is a word, number or a letter that is added before another word. In physics we have different prefixes for the exponential powers of 10, that are placed before units in place of those powers. Some examples are:
deci (d) ------ 10⁻¹
centi (c) ------ 10⁻²
milli (m) ------ 10⁻³
kilo (k) ------ 10³
mega (M) ----- 10⁶
giga (G) ------ 10⁹
We have:
6600 volts
converting to exponential form:
=> 6.6 x 10³ volts
Thus, we know that the prefix of kilo (k) is used for 10³.
Hence,
=> <u>6.6 kilo volts = 6.6 k volts</u>