Answer:
15.24°C
Explanation:
The quality of any heat pump pumping heat from cold to hot place is determined by its coefficient of performance (COP) defined as

Where Q_{in} is heat delivered into the hot place, in this case, the house, and W is the work used to pump heat
You can think of this quantity as similar to heat engine's efficiency
In our case, the COP of our heater is

Where T_{house} = 24°C and T_{out} is temperature outside
To achieve maximum heating, we will have to use the most efficient heat pump, and, according to the second law of thermodynamics, nothing is more efficient that Carnot Heat Pump
Which has COP of:

So we equate the COP of our heater with COP of Carnot heater

Rearrange the equation

Solve this simple quadratic equation, and you should get that the lowest outdoor temperature that could still allow heat to be pumped into your house would be
15.24°C
Answer:
as soon as there is a design to improve
Explanation:
As a design engineer, I started on the "design improvement" step as soon as I had an initial conceptual design.
__
Then, I started that step again when my boss told me, "make it better."
_____
The more interesting question is, "when do you <em>stop</em> the design improvement step?" (Judging by the constant barrage of software updates, that answer is, "never.")
Answer:
Changing oil.
Explanation:
You need to regularly check and change your car’s oil to ensure smooth running of the vehicle and to prolong the lifespan of its engine.
Answer:
All the detailed steps are mentioned in pictures.
Explanation:
See attached pictures.
Answer:
Blank wall
Explanation:
A wall that cannot be moved because it is carrying the weight of the roof is considered a blank wall.