Page 154 - CAPE Green Engineering Syllabus 2016.docx_Neat

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GREEN ENGINEERING
UNIT 2 - PAPER 02
KEY AND MARK SCHEME

Question 3. (continued)

S.O Suggested Response Mark Marks
Allocation KC AK PA

2:2:8 (c)(i) 2 2
2 2
Animals utilize what is called echolocation or 6
bio sonar. This is the biological sonar used 6
by several kinds of animals. Echolocating
animals emit calls to the environment and
listen to the echoes of those calls that
return from various objects near them. They
use these echoes to locate and identify the
objects.

2:2:5 (c)(ii)

Concept development – The idea is to model
echolocation used by animals to locate an
object in the sea.

Product simulation – Utilize computer software
(E.g. MATLAB) to observe how sound waves
travel

2:2:6 (c)(iii)

Experiment to understand basic relationship
between time and possible distance of the lost
ship:
Create a simple electrical prototype using a
computer speaker and built-in microphone. Take
computer to a large empty space such as an
auditorium along with a stop watch. Open sound
wave software on computer. Standing 100m from
auditorium wall, play a loud sound on computer
and look for a change in sound wave when echo
is detected. Start stopwatch when audio sound
(preferably a bang like sound) is played by
computer and stop stopwatch when echo is
detected by sound wave software. Repeat
experiment at 150 m, 200 m and 250 m from wall
and record the respective times.

If a computer is inaccessible you can clap and
listen for echo.