Question 6


6.1 Circumference of the wheel is 60 × 3,14 = 188,4 cm 1 000 metres is 10 000 cm Therefore number of revolutions = 10 000 ÷ 188,4 = 53


6.2 For every revolution of the crank wheel the rear wheel turns three revolutions (60 ÷ 20). Therefore the number of times the crank gear turns to turn the rear wheel 53 times is: 53 ÷ 3 = 17,7


6.3 26 teeth


6.4 Points which could be included: • Many jobs in modern mining do not require physical strength. • Many jobs in mining depend on engineering skills and include Mathematics and Science. Women are equally competent in these skills.


• Mining operations are not only about digging ore out of the ground. There is planning, surveying, truck driving, health and safety roles all of which women are capable of performing.


Question 7 7.1 Input devices in electrical systems provide potential electrical energy 


7.3 Output devices convert electrical potential energy into other forms of energy. These other forms include light, sound, movement and heat energy. 


Question 8


8.1 Potential  8.2 Current  8.3 Potential difference  8.4 Generator  8.5 Solar panels 


Question 9


9 An electrochemical cell is a device that generates  a potential difference  between the electrodes found inside of the cell.  This potential difference is created by chemical reactions.  A normal penlight 1,5 V battery is the most common example of an electrochemical cell.  Photovoltaic cells convert light into electricity.  Sunlight is composed of photons  which are particles of solar energy. 


134


(3) [6]


(2)


7.2 Switches and resistors are used to control or direct current. In systems, this would be regarded as “processing”, as they change the inputs to alter the outputs.  (2)


(2) [6]


(1)


(1) (1)


[5]


[8]


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