The diagram below shows a light ray travelling through an optical fibre. The fibre ismade from two different glass materials known as the core glass and the outercladding glass. These two types of glass materials have different refractive indices. 7.1 State the TWO conditions necessary for total internal reflection to occur. (4) 7.2 Which part … Read more
In Δ PQR, QR = 3 units, PR = x units, PQ = 2x units and PQR = θ.
Methane is used as an alternative fuel. The combustion of methane releases carbondioxide and water. The balanced equation for this reaction is:CH4(g) + O2 (g) → CO2 (g) + 2H2O (g) + 891 kJ.mol-1 The activation energy for this reaction is 172 kJ.mol-1. 7.1 Is this reaction ENDOTHERMIC or EXOTHERMIC? Give a reason for theanswer. … Read more
The equation for the combustion of butane gas is given below. 7.1 Define the term activation energy.(2) 7.2 Is the combustion reaction of butane exothermic or endothermic? Give areason for the answer.(2) 7.3 Draw a sketch graph of potential energy versus course of reaction for thereaction above. Clearly indicate the following on the graph: Activation … Read more
A barium hydroxide solution, Ba(OH)2(aq), reacts with a nitric acid solution, HNO3(aq), according to the following balanced equation: Ba(OH)2(aq) + 2HNO3(aq) → Ba(NO3)2(aq) + 2H2O(ℓ) The potential energy graph below shows the change in potential energy for this reaction. 7.1 Is this reaction ENDOTHERMIC or EXOTHERMIC? Give a reason for the answer. (2) 7.2 Use … Read more
7.1 A company bought machinery costing R80 000. Using the reduced balance method the machinery had a book value of R20 000 after 5 years. Calculate the rate of depreciation. (3) 7.2 Calculate the effective interest rate if interest is compounded at 5% p.a., compounded quarterly (3) 7.3 Sipho invested R30 000 for 6 years. … Read more
An experiment is set up, as shown below, to investigate the effect of slit width on the degree of diffraction. Distance y on the diagram represents the distance between the screen and the single slit. Distance x on the diagram represents the width of the central bright band. 7.1 Write down an investigative question for … Read more
Given the following two functions: 7.1 Determine the 𝑥-intercept of h.(3) 7.2 Sketch neat graphs of h and g on the same set of axes. Clearly show all interceptswith the axes as well as asymptotes. (5) 7.3 Write down the equation of the vertical asymptote of h.(1) 7.4 Determine the coordinates of the points of … Read more
7.1 Draw the graph of f and g for x ∈ [-90° ; 180°] in the SPECIAL ANSWER BOOK. Show all the turning points and intercepts with the axes. Clearly show the asymptotes using dotted lines. (6) 7.2 Determine the values of x, for ∈ [-90° ; 180°], for which f(x) > g(x). (6) 7.3 … Read more
The graph of y = bx is shifted 2 units to the right and 4 units upwards. The shifted graph passes through the point (4 ; 8). 7.1 Calculate the value of b. (4) 7.2 Hence, write down the equation of shifted graph. (1) [5]