WSSS 2021 Prelim P2

1 West Spring Secondary School PRELIMINARY EXAMINATION 2021 Physics 6091/02 Paper 2 Theory SECONDARY 4 EXPRESS Name ( ) Date 01 SEP 2021 Class Duration 1 h 45 min No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer all questions. Candidates are reminded that all quantitative answers should include appropriate units. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of physics than for correct answers. Information for Candidates The number of marks is given in [ ] at the end of each question or part question. FOR EXAMINER’S USE Section A /50 Section B /30 Total /80 This document consists of 16 printed pages including the cover page. Setter Mr Prakash s/o Radakrishna [Turn over]

2 Section A (50 Marks) Answer all questions in this section. 1 Fig. 1.1 shows a motorboat used to pull a 900 N paraglider at a constant speed and height. A rope exerts a force of 1200 N on the paraglider at an angle of 20º to the horizontal. Another force is exerted on the paraglider by the parasail wing. The resultant force acting on the paraglider is 0 N. (a) On Fig. 1.1, draw an arrow to show the direction of the weight. [1] (b) By using a suitable scale drawing, determine the magnitude (size) of the force exerted on the paraglider by the parasail wing and the direction between this force and the horizontal. magnitude of force = ............................................... direction of force = ................................................ [3]

3 2 (a) Define the moment of a force about a point. ........................................................................................................................................................... ........................................................................................................................................................... ...................................................................................................................................................... [2] (b) Fig. 2.1 shows a uniform rod of wood suspended from a pivot. The rod is held stationary by a horizontal force F acting as shown. The mass of the rod is 80 g. The gravitational field strength is 10 N/kg. (i) Calculate the weight W of the rod, weight = .......................................................... [1] (ii) Calculate the force F. Force F = .......................................................... [2] (c) The angle between the rod and the vertical is increased. State whether the force F needed to hold the rod stationary must be increased, decreased or stay the same. Explain your answer. .................................