Physical Science

The gravitational force on a probe, called Curiosity, on the surface of Mars is 3 338 N.The radius of Mars is 3 390 km and the mass of the planet is 6,39 x 1023 kg. 6.1 State Newton’s Law of Universal Gravitation in words. (2) 6.2 Calculate the mass of the probe. (4) 6.3 Calculate … Read more

A crate, with a mass of 25 kg, slides down a plane which is inclined at 15º to thehorizontal. During the first part of the motion, from A to B, there is no friction betweenthe crate and the plane, but part BC has a rough surface. 5.1 Draw a free-body diagram of ALL the forces … Read more

Learners investigate the relationship between the mass of an object and theacceleration it experiences when a constant net force is applied on the object. Theyuse their results to draw the graph below. 4.1 State Newton’s Second Law of Motion in words. (2) 4.2 Calculate the gradient of the graph. (3) 4.3 Hence, determine the net … Read more

A box, with a mass of 45 kg, is pulled with a force of 90 N at an angle of 50º to thehorizontal. The box moves at a CONSTANT VELOCITY. 3.1 Define the term kinetic frictional force. (2) 3.2 State Newton’s First Law of Motion in words. (2) 3.3 Calculate the magnitude of the horizontal … Read more

Two forces, of magnitudes 50 N and 80 N, act at a point on a Cartesian plane in thedirections shown in the sketch below. 2.1 Give the correct term for the following description: A single vector having the same effect as two or more vectors together (1) 2.2 Calculate the: 2.2.1 Magnitude of the vertical … Read more

Various options are provided as possible answers to the following questions. Choosethe answer and write only the letter (A–D) next to the question numbers (1.1 to 1.10) inthe ANSWER BOOK, e.g. 1.11 D. 1.1 Two forces, F1 and F2, act on a point. If F1 and F2 act in the same directionthe maximum resultant has … Read more

Gold and iron extraction are important mining processes in South Africa. Refining takesplace according to the following reactions: Gold is dissolved using cyanide ions (CN–) to extract it from the ore: 4Au(s) + 8NaCN(aq) + 2H2O(ℓ) + O2(g) → 4NaAu(CN)2(aq) + 4NaOH(aq) Iron(lll)oxide is burned in a furnace in the presence of CO: Fe2O3(s) + … Read more

MnO4 (aq) + H+(aq) + H2S(g) → Mn2+(aq) + S(s) + H2O(ℓ) 9.1 Define reduction in terms of oxidation numbers. (2) 9.2 Determine the oxidation number of manganese in the permanganate ion. (1) 9.3 Write down the FORMULA of the substance that undergoes oxidation. (1) 9.4 Explain the answer to QUESTION 9.3 in terms of … Read more