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3 years ago

9

Before taking off a plane travels at a speed of 1/4 km per second. The runaway is 5 km. How many seconds does it take the plane

to get to the end of the runaway?

1 answer:

Vikentia [17]3 years ago

8 0

Answer:

1 5segundos

Explanation:

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The structure of a house is such that it loses heat at a rate of 4500kJ/h per °C difference between the indoors and outdoors. A

adelina 88 [10]

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

$COP=\frac{Q_{in}}{W}$

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

$COP_{heater} = \frac{\frac{4500\ kJ}{3600\ s} *(T_{house}-T_{out})}{4\ kW}$

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:

$COP_{carnot}=\frac{T_{house}}{T_{house}-T_{out}}$

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

$\frac{1.25 *(T_{house}-T_{out})}{4}=\frac{T_{house}}{T_{house}-T_{out}}$

Rearrange the equation

$\frac{1.25}{4}(24-T_{out})^2-24=0$

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

4 0

3 years ago

Plssssssssssssss Alexi is writing a program which prompts users to enter their age. Which function should she use?

aleksandr82 [10.1K]

Answer:

int()

Explanation:

float() is using decimals, so that can't be it, like float(input( "how much does this cost?"))

print() is used to print something, not a user asking, like print("hello")

string() means like a whole, like string( I am good)

By elimination, int() is correct.

Hope this helps!

7 0

3 years ago

How would I get this python code to run correctly? it's not working.

Elanso [62]

Answer:

See Explanation

Explanation:

This question requires more information because you didn't state what the program is expected to do.

Reading through the program, I can assume that you want to first print all movie titles then prompt the user for a number and then print the move title in that location.

So, the correction is as follows:

Rewrite the first line of the program i.e. movie_titles = ["The grinch......."]

for each_movie_titles in movie_titles:

print(each_movie_titles)

usernum = int(input("Number between 0 and 9 [inclusive]: "))

if usernum<10 and usernum>=0:

print(movie_titles[usernum])

Line by line explanation

This iterates through the movie_titles list

for each_movie_titles in movie_titles:

This prints each movie title

print(each_movie_titles)

This prompts the user for a number between 0 and 9

usernum = int(input("Number between 0 and 9 [inclusive]: "))

This checks for valid range

if usernum<10 and usernum>=0:

If number is valid, this prints the movie title in that location

print(movie_titles[usernum])

6 0

3 years ago

What components are included in a basic engine block?

atroni [7]

Houses the CYLINDERS, Water Jacket & Crankcase

8 0

3 years ago

Determine the percent increase in the nominal moment capacity of the section in Problem 2 when including compression steel at to

sergejj [24]

Explanation:

Please kindly share your problem two with us as to know the actual problem we are dealing with, the question looks incomplete

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3 years ago