Bedok Green Prelim P1

2 © BGSS 2024 [Turn over 1 A pipe has an approximate length of 80 cm with an approximate external and internal diameter of 5 cm and 3 cm respectively. Which instruments are the most suitable for measuring accurately the length, external and internal diameters? length external diameter internal diameter A metre rule vernier calipers micrometer B tape metre rule digital calipers C metre rule vernier calipers digital calipers D tape micrometer digital calipers 2 A pendulum is set into motion. As it swings, the angle of oscillation gradually decreases to zero. Which of the following statements about energy at any point of the pendulum’s motion is correct? A The kinetic energy of the pendulum is constant. B The potential energy of the pendulum is constant. C The total energy of the pendulum and air is constant. D The sum of kinetic energy and potential energy of the pendulum is constant. 3 A ball bearing is released in a liquid. It sinks vertically downward until it reaches terminal velocity. Which describes the resultant force acting on the ball bearing during terminal velocity? A constant B decreasing C increasing D zero angle of oscillationangle of oscillation

3 © BGSS 2024 [Turn over 4 Two blocks M and m are connected by a light spring passing over a smooth pulley as shown. When block m is released, the blocks move with constant speed. After a while, the string is cut in between. Which of the following correctly describes the motion of the blocks immediately after the string is cut? M m A stops moving moves with constant speed B moves with constant speed accelerates C decelerates moves with constant speed D decelerates accelerates 5 A block is resting on a table. Two forces act on the block: its weight and the normal contact force. Which force will make an action-reaction pair with the weight of the block? A the force acting on the Earth by the block B the force acting on the table by the block C the force acting on the block by the table D the force acting on the block by the Earth M m

4 © BGSS 2024 [Turn over 6 When a horizontal force of 4.0 N is applied to a wooden block of mass 2.0 kg on a horizontal surface, the block moves with a constant velocity. What is the acceleration of the block if the horizontal force is increased to 12.0 N? A 2.0 m/s2 B 4.0 m/s2 C 6.0 m/s2 D 8.0 m/s2 7 In an experiment to determine the density of lead shots, the following masses, in grams, are obtained. If the density of water is 1 g/cm3, what is the volume of the lead shots in cm3? A m3 – m2 B m3 – m2 – m1 C m3 – m2 + m1 – m0 D m3 + m2 – m1 – m0 m0 empty bottle m1 bottle + lead shots m2 bottle + lead shots + water m3 bottle + water

5 © BGSS 2024 [Turn over 8 The diagram shows a heavy non-uniform wooden plank resting on two supports which act as pivots (not to scale). Three forces F1, F2 and F3 are acting on the plank. The plank is in equilibrium. Which statement is correct? A F1 is larger than F2. B F2 is larger than F1. C The sum of F1 and F2 is twice of F3. D F3 is larger than the sum of F1 and F2. 9 A non-uniform object is placed on an inclined plane. The object is just about to topple. Which position is the centre of gravity? non-uniform object inclined plane

6 © BGSS 2024 [Turn over 10 The diagram shows two liquids, P and Q, which do not mix. The liquids are in equilibrium in an open U-tube. . What is the ratio of density of Pdensity of Q ? A 2 / 5 B 3 / 5 C 2 / 3 D 3 / 2 11 A builder leaves two identical, heavy, stone tiles resting on soft earth. One is vertical and the other is horizontal. Which row correctly compares the forces and the pressures that the tiles exert on the earth? forces pressures A different different B different same C same different D same same Q P 3 cm 2 cm P Q

7 © BGSS 2024 [Turn over 12 Some air is trapped in the space above the mercury in a barometer. The glass tube is pressed down into the mercury bath. Which of the following best describes the change of l, the height of air column, and h, the height of mercury column? l h A decrease remain unchanged B remain unchanged decrease C decrease decrease D increase decrease 13 A gas in a sealed cylinder with fixed volume is heated. Which of the following does not increase as the gas is heated? A the average distance between the gas molecules B the average kinetic energy of the gas molecules C the average number of collisions between gas molecules D the frequency of gas molecules hitting the cylinder walls lairmercuryh l h

8 © BGSS 2024 [Turn over 14 The diagram shows an automatic dispenser of hot water which is used in a tea maker. When the water boils, it rushes out through the pipe into the cup. The main cause of this is due to A the expansion of water in the tea maker. B the expansion of the air above the water. C the steam pressure building up inside when the water boils. D the formation of convection currents in the water when it boils. 15 Air is blown through a tube containing some ether. Underneath the beaker is a small pool of water as shown in the diagram below. Which of the following best describes what happens? ether water A boils evaporates B evaporates freezes C condenses evaporates D freezes boils heating element water

9 © BGSS 2024 [Turn over 16 On a warm afternoon, Amy submerges her hands in water. Heat is transferred from her skin to the water. Which of the following is the main heat transfer process? A conduction B convection C evaporation D radiation 17 A bunsen burner is lighted above a copper gauze as shown below. There is no flame below the gauze because A there is no gas below the gauze. B heat is conducted away by the gauze. C heat is radiated from the copper gauze. D convection current is created below the gauze. 18 Water in a kettle boils and turns into steam. What is happening to the water molecules? A They are losing energy. B They are moving faster. C They are moving further apart. D They are expanding and getting lighter. flame copper gauze bunsen burner

10 © BGSS 2024 [Turn over