OxfordAQA International GCSE Physics: Forces, Hooke's law, vectors and distance-time motion (9203) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions are aligned to the OxfordAQA International GCSE Physics (9203) specification, version 5.2, for exams May/June 2018 onwards, sections 3.1.1 and 3.1.2. Where a question needs a value of g it is given in the question.

Related pages: course hub, printable checklist, forces practice questions and the free 10-minute diagnostics.

Questions

1. State whether each force is a contact force or a non-contact force.

(a) the tension in a crane cable [1] (b) the pull of a magnet on a steel paper clip [1] (c) friction on a crate sliding across a floor [1] (d) the force between a charged balloon and a wall [1]

2. The list shows six quantities: distance, momentum, speed, acceleration, time, displacement. Write down the three that are vectors. [3]

3. A rover has a mass of 185 kg. On the Moon, g = 1.6 N/kg. On Earth, g = 9.8 N/kg.

(a) Calculate the weight of the rover on the Moon. [2] (b) A rock sample weighs 6.0 N on Mars, where g = 3.7 N/kg. Calculate its mass. [2] (c) The rover is returned to Earth. State what happens to its mass and to its weight. [2]

4. (a) A force of 18 N acts to the left on a trolley. Describe how to draw this force as an arrow, using a scale of 1 cm to 6 N. [2] (b) A swimmer pushes backwards on the water with a force of 40 N. State the size and direction of the force the water exerts on the swimmer, and say which object it acts on. [2]

5. (a) Explain why the brake blocks of a bicycle become warm when the brakes are applied. [2] (b) Explain why a cyclist who crouches low over the handlebars can travel faster for the same effort. [2]

6. A student hangs a load on a spring of original length 10.0 cm and removes it.

(a) The spring returns to 10.0 cm. State the type of distortion. [1] (b) After a much heavier load is removed the spring is 10.8 cm long. State what this shows and name the type of distortion. [2]

7. A spring has a spring constant of 80 N/m and an original length of 15.0 cm. Assume the limit of proportionality is not exceeded.

(a) Calculate the extension produced by a force of 3.2 N. Give your answer in cm. [2] (b) Calculate the force needed to produce an extension of 7.5 cm. [2] (c) State the length of the spring when the 3.2 N force acts. [1]

8. A student investigates a spring and records the results.

Force (N)	0	0.5	1.0	1.5	2.0	2.5	3.0
Extension (cm)	0	2.0	4.0	6.0	8.0	10.0	15.0

(a) Describe the pattern shown by the results and state where it changes. [2] (b) State the limit of proportionality. [1] (c) Calculate the spring constant in N/m. [2] (d) Predict the extension for a force of 1.8 N. [1] (e) Compare the measured extension at 3.0 N with the extension predicted by direct proportion. [1]

9. Describe how you would carry out an investigation of the relationship between force and extension for a spring. Include how you would reduce error and keep the investigation safe. [6]

10. A skater moves in a straight line. Her distance from the start is recorded.

Time (s)	0	12	22	40
Distance (m)	0	30	30	84

The motion is uniform between each pair of readings.

(a) Calculate her speed during the first 12 s. [2] (b) Describe her motion from 12 s to 22 s. [1] (c) Calculate her speed from 22 s to 40 s. [1] (d) Calculate her average speed for the whole 40 s. [2]

11. A walker goes 240 m east in 150 s, then 60 m west in 90 s.

(a) Calculate the average speed for the whole walk. [2] (b) State the displacement of the walker from the start. [1] (c) Calculate the average velocity, giving its direction. [2]

12. A mass of 0.60 kg hangs from a spring of spring constant 49 N/m. On Earth, g = 9.8 N/kg. On the Moon, g = 1.6 N/kg.

(a) Calculate the weight of the mass on Earth. [2] (b) Calculate the extension of the spring on Earth, in cm. [2] (c) Calculate the extension of the spring when the same mass hangs from it on the Moon, in cm. [3] (d) Explain why the mass has the same value in both places but the extension differs. [1]

Answers

1. (a) contact [1] (b) non-contact [1] (c) contact [1] (d) non-contact [1] Examiner insight: A one-word answer is enough here. Tension and friction need touching surfaces, while magnetic, electrostatic and gravitational forces act through a field.

2. Momentum [1], acceleration [1], displacement [1]. Distance, speed and time are scalars. Examiner insight: Give exactly the number asked for, because a wrong extra answer can contradict a right one.

3. (a) W = m × g = 185 × 1.6 [1] = 296 N [1] (b) m = W ÷ g = 6.0 ÷ 3.7 [1] = 1.6 kg (1.62 kg) [1] (c) The mass stays the same (185 kg) [1]. The weight increases, to 185 × 9.8 = 1813 N, about 1800 N [1] Examiner insight: Writing the equation and the substitution shows your method clearly. In part (c), say “mass is unchanged” explicitly.

4. (a) Calculate the length: 18 ÷ 6 = 3.0 cm [1]. Draw a horizontal arrow 3.0 cm long with the head on the left [1] (b) 40 N [1], forwards, acting on the swimmer [1] Examiner insight: The arrow needs a length from the scale and a clear head. In part (b), say which object feels the force.

5. (a) Friction acts between the blocks and the wheel rim, impeding the motion [1]. Work done against friction increases the internal (thermal) energy of the blocks, so they warm up [1] (b) Crouching presents a smaller area to the air [1], so there is less air resistance, and the same driving force gives a higher speed [1] Examiner insight: “Friction causes heat” is thin. Say where the friction acts and what happens to the energy. For part (b), link the smaller area to less air resistance.

6. (a) Elastic distortion [1] (b) The spring has not returned to its original length, so the distortion is inelastic [1]. It has been permanently stretched by 0.8 cm [1] Examiner insight: Compare the final length with the original length in your answer. Saying “it is damaged” without referring to the shape or length does not show the idea.

7. (a) e = F ÷ k = 3.2 ÷ 80 [1] = 0.040 m = 4.0 cm [1] (b) e = 7.5 cm = 0.075 m [1]; F = k × e = 80 × 0.075 = 6.0 N [1] (c) Length = 15.0 + 4.0 = 19.0 cm [1] Examiner insight: Converting to metres is a separate step that earns or loses credit. In part (c), the question asks for the length, so the extension alone is not the answer.

8. (a) Up to 2.5 N the extension increases by equal amounts for equal increases in force, so it is directly proportional to force [1]. At 3.0 N the extension rises by more than expected (the pattern changes after 2.5 N) [1] (b) 2.5 N [1] (c) Use a point in the proportional region, for example 2.0 N and 8.0 cm = 0.080 m: k = 2.0 ÷ 0.080 [1] = 25 N/m [1] (d) e = 1.8 ÷ 25 = 0.072 m = 7.2 cm [1] (e) Direct proportion would give 3.0 ÷ 25 = 0.120 m = 12.0 cm, but the measured value is 15.0 cm, which is 3.0 cm more [1] Examiner insight: Quote values from the table. Find k from the straight part of the data, not the final point.

9. Any six of the following points, in your own words.

• Clamp the spring vertically with a rule beside it [1]
• Measure the original length with no load [1]
• Add known masses one at a time and calculate the force from W = m × g [1]
• Measure the new length each time with the eye level with the pointer to avoid parallax, and repeat to find a mean [1]
• Calculate extension = length − original length, then plot force against extension and look for a straight line through the origin [1]
• Safety: eye protection, a stable stand, feet clear of the masses, and do not overload the spring (any one) [1] Examiner insight: Name the measurements and give the steps in a sensible order. A list of equipment, or “measure the spring” without saying what is measured, gains little.

10. (a) speed = distance ÷ time = 30 ÷ 12 [1] = 2.5 m/s [1] (b) She is stationary (distance stays at 30 m) [1] (c) (84 − 30) ÷ (40 − 22) = 54 ÷ 18 = 3.0 m/s [1] (d) total distance 84 m, total time 40 s: 84 ÷ 40 [1] = 2.1 m/s [1] Examiner insight: In part (b), calling a flat line steady movement is wrong. In part (d), averaging 2.5, 0 and 3.0 gives a different value and ignores that the stages last different times.

11. (a) total distance = 240 + 60 = 300 m, total time = 150 + 90 = 240 s [1]; average speed = 300 ÷ 240 = 1.25 m/s [1] (b) 240 − 60 = 180 m east [1] (c) v = s ÷ t = 180 ÷ 240 [1] = 0.75 m/s east [1] Examiner insight: A vector answer needs a direction as well as a size, so state the direction. Do not use 300 m in part (c), because velocity uses displacement.

12. (a) W = m × g = 0.60 × 9.8 [1] = 5.88 N (5.9 N) [1] (b) e = F ÷ k = 5.88 ÷ 49 [1] = 0.12 m = 12 cm [1] (c) Weight on the Moon = 0.60 × 1.6 = 0.96 N [1]; e = 0.96 ÷ 49 = 0.0196 m [1] = 2.0 cm [1] (d) Mass is the amount of matter in the object and does not depend on g; weight depends on g, so the force on the spring and its extension change [1] Examiner insight: Carry unrounded values forward and round only at the end. Explain part (d) in terms of weight and mass separately.

Where marks are usually lost

• Using the length of the spring in F = k × e instead of the extension.
• Leaving extension in cm when the spring constant is in N/m.
• Describing a horizontal distance-time line as steady movement.
• Averaging the speeds of different stages instead of dividing total distance by total time.
• Giving a velocity or displacement with no direction.
• Choosing the last point of a force-extension table, which is beyond the limit of proportionality, to calculate k.
• Saying friction “makes heat” without saying which surfaces are involved.

Next steps

• Revise with the revision notes and the study guide.
• Visit the course hub and the checklist.
• Take the free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

OxfordAQA International GCSE Physics (9203) specification, version 5.2, for exams May/June 2018 onwards, published by Oxford International AQA Examinations. Sections 3.1.1 and 3.1.2, and the required practical on force and extension for a spring.