P6 Science SA1 2025 — Methodist Girls

The diagram below shows a rollercoaster track. Which of the following graphs correctly shows the amount of gravitational force acting on the roller coaster at points P, Q and R? [Graphs: (1) bar chart with P tallest, Q shortest, R medium; (2) bar chart with P medium, Q shortest, R tallest; (3) bar chart with P short, Q absent/zero, R tall; (4) bar chart with P, Q and R all equal heights.]

A ball was released from point X and rolled down the plank pass Y before coming to a stop on the table, as shown in the diagram. Which of the following actions would make the ball travel a longer distance before stopping? A. Release the ball from point Y B. Apply a layer of oil on the ball C. Replace the block with a taller block D. Cover the surface of the table with sandpaper

Which term is given to the birds shown in the diagram?

Kelly wanted to study the food relationship between animals A, B and X. Animals A, B and X had no disease. Animal X feeds only on plants. At the start of the experiment, Kelly placed a few animals A and X in a tank with some plants. She counted the number of each animal at the end of every week. After two weeks, she added a few animal B to the tank. The graph below shows her results. [Graph: size of population versus week from 0 to 5. Animal X starts high, decreases until about week 2-3 (lowest point), then increases sharply to be the highest by week 5. Animal A starts moderate, stays roughly steady for the first 2 weeks, then decreases steadily to a very low value by week 5. Animal B is introduced at week 2 starting low, rises to a peak around week 3-4 and then levels off / slightly decreases, ending higher than A but lower than X.] Which of the following is correct? A. Animal B fed on animal A. B. Animal B fed on animal X. C. Animal A fed on animal X. D. Animal A fed on animal B.

Diagram 1 below shows the original length of a spring. [Diagram 1: a spring hanging from the ceiling with its original length of 3 cm, sitting above a table.] A button magnet is attached to the spring, as shown in Diagram 2. A bar magnet is then placed under the button magnet, as shown in Diagram 3. Arrows P, Q and R show the forces acting on the button magnet. [Diagram 2: the spring is now stretched to 7 cm with a button magnet hanging at its lower end; arrow P points upward on the button magnet and arrow Q points downward on the button magnet. Diagram 3: a bar magnet is placed under the button magnet; the spring is now only 5 cm long (shorter than in Diagram 2), and arrow R points upward on the button magnet from the direction of the bar magnet.] Which of the following correctly identifies the forces P, Q and R? [Table of options: (1) P = elastic spring force, Q = gravitational force, R = magnetic force; (2) P = frictional force, Q = gravitational force, R = elastic spring force; (3) P = frictional force, Q = elastic spring force, R = magnetic force; (4) P = elastic spring force, Q = frictional force, R = magnetic force.]

The diagram below shows a pen holder with a magnet attached at the back. The pen holder is used to hold a piece of paper to the metal cabinet as shown below. [Diagram: a metal cabinet (like a fridge/filing cabinet) with the pen holder stuck on its front, sandwiching a piece of paper between the magnet at the back of the pen holder and the metal cabinet.] Which of the following statements is/are correct? A. There is gravitational attraction between the pen holder and the earth. B. There is friction between the paper and the magnet behind the pen holder. C. There is magnetic attraction between the paper and the magnet behind the pen holder.

Gayle hung three identical springs each attached to identical blocks of equal mass onto a retort stand. What would she see?

Ruo Lin carried out an experiment to find out how the presence of light affects the growth of a plant as shown below. She placed one plant in a glass tank covered with black paper and another plant in a glass tank covered with tracing paper. She placed both set-ups in the same classroom. Which of the following set-ups should Ruo Lin use as a control in this experiment? [Options: (1) potted plant inside a glass tank covered with newspaper; (2) potted plant inside an uncovered glass tank; (3) potted plant inside an uncovered bigger glass tank; (4) potted plant inside an uncovered glass tank.]

Emily carried out an experiment to investigate the force needed to move a wooden block on different types of surfaces. The diagram below shows the set-up for Surface W. A 20g weight was added one at a time until the wooden block just started to move. The experiment was repeated using surfaces X, Y and Z. The weight required to move the wooden block on each surface is shown in the table below. [Table: Surface W – 120 g; Surface X – 80 g; Surface Y – 160 g; Surface Z – 140 g.] (a) State the relationship between the weight required to move the wooden block and the frictional force between the block and the type of surface. [1] (b) Whenever a driver steps on the brakes, the car will continue to move before it stops completely. This is called the braking distance. Based on the results in the table, arrange the braking distance of a car when it moves on surfaces W, X, Y and Z, from longest to shortest. [1] (c) Would the braking distance of a car be shorter, longer, or the same if the road is wet? Explain your answer. [2]

Female Aedes mosquitoes spread dengue in humans. The graphs below show data taken from a neighbourhood in Singapore. [Graph 1: amount of rainfall (mm) versus month, Jan–Dec. Rainfall starts very low (~20–40 mm) in Jan, rises steadily each month, peaks at about 240 mm in August, then decreases steadily back down to about 40 mm by December.] [Graph 2: population of female Aedes mosquitoes versus month, Jan–Dec. Population stays very low (~20–30) from Jan to April, rises sharply from May, peaks at about 250 in August, then decreases steadily back down to about 30 by December.] (a) Describe the relationship between the amount of rainfall and the population of female Aedes mosquitoes from January to December. [1] (b) Explain your answer in (a). [1] Scientists released male mosquitoes infected with bacteria W into the neighbourhood as shown in the diagram below. Male mosquitoes infected with bacteria W do not bite or spread diseases. When they mate with female Aedes mosquitoes, the eggs laid by the female mosquitoes do not hatch. (c) The number of dengue cases in the neighbourhood decreased after the release of infected male mosquitoes. Explain why. [1]

A scientist made the following observations of organisms A, B, C, D and E. • D is a food producer. • B and C feeds on D. • A lives on land and feeds on C and E. • C lives in both land and water. • C and E feeds on B, B lives in water. (a) Complete the food web to show the relationship among all the organisms above. [2] Organism C builds a nest in water as shown in the diagram below. [Diagram: a beaver-like organism C standing on top of a dome-shaped nest made of sticks built partly above water; the entrance to the nest is underwater, with more organisms C swimming under the water.] (b) Using the food web in (a) and the information above, suggest two advantages of the nest for the survival of C. Explain your answer. [2]

The diagram below shows a pond habitat. (a) Other than being a source of food, state another reason plants J and K are important to the fishes in the pond. [1] (b) Explain why the population of plant J decreases when the population of plant K increases. [1] (c) When a lot of plant J die and start to rot, the oxygen level in the pond becomes lower. Give a reason why the rotting plants cause a decrease in the level of oxygen. [1]