\[ \begin{align}\begin{aligned}\newcommand\blank{~\underline{\hspace{1.2cm}}~}\\% Bold symbols (vectors) \newcommand\bs[1]{\mathbf{#1}}\\% Differential \newcommand\dd[2][]{\mathrm{d}^{#1}{#2}} % use as \dd, \dd{x}, or \dd[2]{x}\\% Poor man's siunitx \newcommand\unit[1]{\mathrm{#1}} \newcommand\num[1]{#1} \newcommand\qty[2]{#1~\unit{#2}}\\\newcommand\per{/} \newcommand\squared{{}^2} \newcommand\cubed{{}^3} % % Scale \newcommand\milli{\unit{m}} \newcommand\centi{\unit{c}} \newcommand\kilo{\unit{k}} \newcommand\mega{\unit{M}} % % Percent \newcommand\percent{\unit{{\kern-4mu}\%}} % % Angle \newcommand\radian{\unit{rad}} \newcommand\degree{\unit{{\kern-4mu}^\circ}} % % Time \newcommand\second{\unit{s}} \newcommand\s{\second} \newcommand\minute{\unit{min}} \newcommand\hour{\unit{h}} % % Distance \newcommand\meter{\unit{m}} \newcommand\m{\meter} \newcommand\inch{\unit{in}} \newcommand\foot{\unit{ft}} % % Force \newcommand\newton{\unit{N}} \newcommand\kip{\unit{kip}} % kilopound in "freedom" units - edit made by Sri % % Mass \newcommand\gram{\unit{g}} \newcommand\g{\gram} \newcommand\kilogram{\unit{kg}} \newcommand\kg{\kilogram} \newcommand\grain{\unit{grain}} \newcommand\ounce{\unit{oz}} % % Temperature \newcommand\kelvin{\unit{K}} \newcommand\K{\kelvin} \newcommand\celsius{\unit{{}^\circ C}} \newcommand\C{\celsius} \newcommand\fahrenheit{\unit{{}^\circ F}} \newcommand\F{\fahrenheit} % % Area \newcommand\sqft{\unit{sq\,\foot}} % square foot % % Volume \newcommand\liter{\unit{L}} \newcommand\gallon{\unit{gal}} % % Frequency \newcommand\hertz{\unit{Hz}} \newcommand\rpm{\unit{rpm}} % % Voltage \newcommand\volt{\unit{V}} \newcommand\V{\volt} \newcommand\millivolt{\milli\volt} \newcommand\mV{\milli\volt} \newcommand\kilovolt{\kilo\volt} \newcommand\kV{\kilo\volt} % % Current \newcommand\ampere{\unit{A}} \newcommand\A{\ampere} \newcommand\milliampereA{\milli\ampere} \newcommand\mA{\milli\ampere} \newcommand\kiloampereA{\kilo\ampere} \newcommand\kA{\kilo\ampere} % % Resistance \newcommand\ohm{\Omega} \newcommand\milliohm{\milli\ohm} \newcommand\kiloohm{\kilo\ohm} % correct SI spelling \newcommand\kilohm{\kilo\ohm} % "American" spelling used in siunitx \newcommand\megaohm{\mega\ohm} % correct SI spelling \newcommand\megohm{\mega\ohm} % "American" spelling used in siunitx % % Capacitance \newcommand\farad{\unit{F}} \newcommand\F{\farad} \newcommand\microfarad{\micro\farad} \newcommand\muF{\micro\farad} % % Inductance \newcommand\henry{\unit{H}} \newcommand\H{\henry} \newcommand\millihenry{\milli\henry} \newcommand\mH{\milli\henry} % % Power \newcommand\watt{\unit{W}} \newcommand\W{\watt} \newcommand\milliwatt{\milli\watt} \newcommand\mW{\milli\watt} \newcommand\kilowatt{\kilo\watt} \newcommand\kW{\kilo\watt} % % Energy \newcommand\joule{\unit{J}} \newcommand\J{\joule} % % Composite units % % Torque \newcommand\ozin{\unit{\ounce}\,\unit{in}} \newcommand\newtonmeter{\unit{\newton\,\meter}} % % Pressure \newcommand\psf{\unit{psf}} % pounds per square foot \newcommand\pcf{\unit{pcf}} % pounds per cubic foot \newcommand\pascal{\unit{Pa}} \newcommand\Pa{\pascal} \newcommand\ksi{\unit{ksi}} % kilopound per square inch \newcommand\bar{\unit{bar}} \end{aligned}\end{align} \]

Dec 04, 2025 | 281 words | 3 min read

7.2.3. Task 3#

Learning Objectives#

Read and interpret a flowchart that contains user-defined functions; Design a program with user-defined functions; Understand the execution sequence for a program with user-defined functions.

Introduction#

As the scripts and programs we write become more complex, we often do not want to put all of our code directly in the main function. Python allows users to easily write their own functions in order to modularize their programs; these are called user-defined functions.

Task Instructions#

You find yourself abandoned on an unknown planet. However, since you are an aspiring engineer, you plan to design a rocket cable of getting you back home. As part of this, you need to write a program that estimates the minimum velocity your rocket must achieve to escape the gravitational field of this mystery planet. Commonly known as the escape velocity. You however, are only aware of the average density of the planet and its radius. A flowchart for that program is shown in Fig. 7.1. Find the output of the program given the following initial conditions:

Table 7.6 Cases for M05 team task 3#

\(\rho\) (\(\frac{\kilo\gram}{\meter^3}\))

\(r\) (\({\meter}\))

\(G\) (\(\frac{\meter^{3}}{\kilo\gram\times\second^{2}}\))

5513.0

6371000

\(6.6743\times 10^{-11}\)

1879.8

2574730

\(6.6743\times 10^{-11}\)

The escape velocity of a projectile is given by:

(7.1)#\[v_e = \sqrt{\frac{2Gm}{r}}\]

Where

  • \(v_e\) is the escape velocity

  • \(G\) is the gravitational constant

  • \(m\) is the mass of the planet

  • \(r\) is the radius of the planet

The mass of the planet is given by:

(7.2)#\[m = \rho \times V\]

Where

  • \(\rho\) is the planet’s average density

  • \(V\) is the volume

The volume of a sphere is given by (we approximate the planet’s shape to be a sphere):

(7.3)#\[V = \frac{4}{3}\times\pi\times r^{3}\]

Where

  • r is the radius

Note

Convert the radius from m to km before printing to the terminal. This can be done using simple division in Python

../../../../../_images/flowchart.png

Fig. 7.1 Flowchart for Team Task 3#

Save your answers to a PDF named py1_team_3_teamnumber.pdf.

Table 7.7 Deliverables#

Deliverables

Description

py1_team_3_teamnumber.pdf

PDF with answers to the task