Further Mechanics, Fields and Particles

Worked examples (9)

• 1Impulse from force and contact time (2 marks)
• 2Kinetic energy from momentum, $E_k = p^2/2m$ (2 marks)
• 3Elastic or inelastic? (3 marks)
• 4Force from a change of momentum (4 marks)
• 5Impulse as the area under a force–time graph (4 marks)
• 6Recoil in an explosion using conservation of momentum (5 marks)
• 7Two-dimensional collision — resolving momentum (6 marks)
• 8Momentum vector triangle for an explosion (6 marks)
• 9Core Practical 9 — force equals rate of change of momentum (6 marks)

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Worked examples (9)

• 1Angular velocity from rotational speed (2 marks)
• 2Centripetal acceleration of a whirled ball (2 marks)
• 3Period and speed from angular velocity (3 marks)
• 4Conical pendulum — tension and speed (4 marks)
• 5Maximum cornering speed on a flat bend (4 marks)
• 6Tension in a horizontal circle from frequency (5 marks)
• 7Vertical circle: minimum speed at the top (5 marks)
• 8Vertical circle: tension at top and bottom (6 marks)
• 9Orbital speed from gravity as the centripetal force (6 marks)

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Worked examples (9)

• 1Capacitance from charge and voltage (2 marks)
• 2Charge stored on a capacitor (2 marks)
• 3Energy stored on a capacitor (3 marks)
• 4Energy stored using Q²/2C (4 marks)
• 5Charge remaining during discharge (4 marks)
• 6Voltage during charging (4 marks)
• 7Determining RC from a ln Q vs t graph (6 marks)
• 8Time for the p.d. to fall to a given fraction (5 marks)
• 9Capacitors in series and parallel with energy (6 marks)

Model answers (10)

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• ✓Model answer — Adapted from Edexcel IAL Physics Unit 4 (CP11)
• ✓Model answer — Adapted from Edexcel IAL Physics Unit 4 (CP11)
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• ✓Model answer — Adapted from Edexcel IAL Physics Unit 4 (CP11)

Worked examples (9)

• 1Reading nuclide notation (2 marks)
• 2Identifying isotopes (2 marks)
• 3Speed of an electron accelerated through a p.d. (3 marks)
• 4Converting an energy in electronvolts to joules (3 marks)
• 5Radius of a proton's path in a cyclotron (3 marks)
• 6Why the cyclotron frequency is independent of speed (4 marks)
• 7Closest approach of an alpha particle to a nucleus (4 marks)
• 8de Broglie wavelength and probing the nucleus (5 marks)
• 9Interpreting the alpha-scattering results (6 marks)

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Worked examples (9)

• 1Force on a current-carrying wire (perpendicular) (2 marks)
• 2Finding the magnetic flux density (2 marks)
• 3Force on a moving charged particle (2 marks)
• 4Force on a wire at an angle to the field (3 marks)
• 5Radius of an electron's circular path (4 marks)
• 6Magnetic flux and flux linkage in a coil (3 marks)
• 7Induced e.m.f. from Faraday's law (4 marks)
• 8Radius of a proton path and its momentum (5 marks)
• 9Why the magnetic force does no work (6 marks)

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Worked examples (9)

• 1Energy equivalent of the electron mass (2 marks)
• 2Converting an electron's energy to MeV (2 marks)
• 3Classifying particles: hadron, baryon, meson or lepton (3 marks)
• 4Photon energy from electron–positron annihilation (4 marks)
• 5Minimum photon energy for pair production (4 marks)
• 6Is a proposed interaction allowed? (5 marks)
• 7Beta-minus decay at quark level (5 marks)
• 8Energy released from a mass change in u and MeV (6 marks)
• 9Why a proposed decay is forbidden (6 marks)

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