4.1 In the diagram below, a 2 kg block is connected to a 1 kg block by means of alight inextensible string. The blocks are pulled up an inclined plane, whichforms an angle of 28o to the horizontal. The sides of the blocks which touchthe inclined plane have the same area. The kinetic frictional force … Read more
A constant force, F, pulls a 50 kg block at a constant speed over a rough horizontalsurface, AB, as shown in the diagram below. The coefficient of kinetic friction (μk)between the block and the surface is 0,4. 3.1 Draw a labelled free-body diagram showing ALL the forces acting on theblock. (4) 3.2 State Newton’s first … Read more
Gold and iron are two of many minerals mined in South Africa. Iron is mined inopen-cast mines, while gold is usually found in deep-shaft (underground) mines.During the process of refining, the following chemical reactions take place to extractthe metal from the ore: Gold is dissolved in a solution containing cyanide ions (CN–) to extract it … Read more
The discovery of gold played a significant role in the economic development of SouthAfrica. In 1970 gold mining in South Africa contributed 68 per cent to global production. 10.1 Which TWO mining methods are used in South Africa? (2) 10.2 Give TWO reasons why mining is important for the South African economy. (2) 10.3 State … Read more
A silver Christmas tree can be made by placing copper wire, shaped in the form ofa tree, into a silver nitrate solution. The unbalanced equation for the reaction is: Cu(s) + AgNO3(aq) → Cu(NO3)2(aq) + Ag(s) 9.1 Define the term oxidation in terms of oxidation number. (2) 9.2 Write down the following for the reaction … Read more