Total marks: 70 · Duration: 75 minutes · Tier: Higher
Instructions to candidates
- Use black ink or black ball-point pen. Draw diagrams in pencil.
- Answer all questions in the spaces provided.
- In all calculations, show clearly how you work out your answer.
- You may use a calculator.
- Where a question describes a graph, diagram or apparatus in words, you may find it helpful to sketch it.
Information
- The maximum mark for this paper is 70.
- The marks for questions are shown in brackets.
- You are expected to use good English and to organise information clearly, especially in questions marked with an asterisk (*).
- This paper covers AQA GCSE Combined Science: Trilogy physics topics 6.5 to 6.7: forces; waves; and magnetism and electromagnetism.
- Take the gravitational field strength g = 9.8 N/kg.
- Equations you may need that are on the AQA Physics equations sheet: (final velocity)² − (initial velocity)² = 2 × acceleration × distance; elastic potential energy = ½ × spring constant × (extension)²; period = 1 ÷ frequency; force on a conductor = magnetic flux density × current × length.
Paper
Question 1 — Forces (8 marks)
(a) Explain the difference between a scalar quantity and a vector quantity. Give one example of each. [2 marks]
(b) Two tugs pull a barge. One tug pulls with a force of 12 kN due east. The other pulls with a force of 5 kN due north.
Calculate the size of the resultant force on the barge. [2 marks]
(c) Calculate the weight of a climber of mass 65 kg on Earth. [2 marks]
(d) A force of 3.0 N stretches a spring by 0.12 m. The spring has not passed its limit of proportionality.
Calculate the spring constant. [2 marks]
Question 2 — Investigating force and acceleration (9 marks)
A student investigates how the acceleration of a trolley depends on the resultant force on it. A string attached to the trolley passes over a pulley at the end of the bench to a hanging mass holder. The trolley passes through two light gates, which record its speed at each gate and the time it takes to travel between them.
(a) In one run, the speed at the first light gate is 0.20 m/s and the speed at the second is 0.80 m/s. The time taken between the gates is 1.5 s.
Calculate the acceleration of the trolley. [2 marks]
(b) To increase the force, the student moves masses from the trolley onto the mass holder instead of adding new masses. Explain why. [2 marks]
(c) The student's graph of acceleration against force is a straight line through the origin. What does this show? [1 mark]
(d) The total mass of the trolley, the masses and the holder is 0.80 kg. Calculate the resultant force needed to give an acceleration of 0.40 m/s². [2 marks]
(e) What is meant by the inertial mass of an object? [1 mark]
(f) Suggest how the student could reduce the effect of friction on the results. [1 mark]
Question 3 — Motion (10 marks)
(a) Give a typical walking speed for a person, in m/s. [1 mark]
(b) A cyclist accelerates uniformly from rest to 8.0 m/s in 5.0 s. Calculate the acceleration. [2 marks]
(c) A car is travelling at 15 m/s. The driver brakes and the car decelerates uniformly at 4.5 m/s² until it stops.
Calculate the braking distance. [3 marks]
(d) The mass of the car and driver is 1400 kg. Calculate the braking force. [2 marks]
(e) The car later travels along a motorway at a constant velocity of 30 m/s. The engine is still providing a driving force. Explain why the car does not accelerate. [2 marks]
Question 4 — Stopping distances (9 marks)
(a)* The stopping distance of a car is the sum of the thinking distance and the braking distance.
Explain how the condition of the driver, the car and the road can affect the stopping distance. In your answer, explain why driving faster increases the braking distance by more than it increases the thinking distance. [6 marks]
(b) Give a typical range of values for human reaction time. [1 mark]
(c) A driver has a reaction time of 0.80 s and is travelling at 13 m/s. Calculate the thinking distance. [2 marks]
Question 5 — Momentum (8 marks)
(a) A cricket ball of mass 0.16 kg travels at 25 m/s. Calculate its momentum. Give the unit. [2 marks]
(b) Trolley A, of mass 2.0 kg, moves at 3.0 m/s towards trolley B, of mass 1.0 kg, which is stationary. The trolleys collide and stick together.
Calculate their velocity just after the collision. [3 marks]
(c) State the principle of conservation of momentum. [1 mark]
(d) Show that kinetic energy is not conserved in the collision in part (b). [2 marks]
Question 6 — Waves (10 marks)
(a) Describe the difference between transverse waves and longitudinal waves. [2 marks]
(b) A student uses a ripple tank to produce water waves with a frequency of 4.0 Hz. The student places a ruler beside the shadows of the waves on the floor and finds that 10 wavelengths cover a distance of 0.60 m.
Calculate the speed of the water waves. [3 marks]
(c) Explain why the student measures the length of 10 waves instead of measuring one wave. [1 mark]
(d) Calculate the period of the waves. [1 mark]
(e) The waves pass into shallower water where their speed is 0.16 m/s. The frequency does not change. Calculate the new wavelength. [2 marks]
(f) The waves reach the boundary with the shallower water at an angle. State what happens to their direction of travel. [1 mark]
Question 7 — Electromagnetic waves (8 marks)
(a) Name the type of electromagnetic wave between visible light and X-rays in the electromagnetic spectrum. [1 mark]
(b) Give one use of microwaves and one use of infrared radiation. [2 marks]
(c) Explain how radio waves are produced by a transmitter and how they are detected by a receiver aerial. [2 marks]
(d) Explain why X-rays and gamma rays are more hazardous to the human body than radio waves. [2 marks]
(e) A student uses a hollow metal cube filled with hot water to investigate how much infrared radiation different surfaces emit. The four faces are matt black, shiny black, matt white and shiny silver. Which face emits the most infrared radiation? [1 mark]
Question 8 — Magnetism and electromagnetism (8 marks)
(a) Explain the difference between a permanent magnet and an induced magnet. [2 marks]
(b) Describe how a student could use a small plotting compass to plot the magnetic field lines around a bar magnet. [2 marks]
(c) Give two ways of increasing the strength of the magnetic field of a solenoid. [2 marks]
(d) A wire of length 0.050 m carries a current of 2.5 A at right angles to a magnetic field of flux density 0.40 T. Calculate the force on the wire. [2 marks]