Unit 3: Gravity and Electromagnetism

A focused answer to the WACE Year 12 Physics Unit 3 content point on generators. How a rotating coil induces a sinusoidal emf, the role of slip rings versus a commutator, the shape of the output, and what controls the peak voltage.

A focused answer to the WACE Year 12 Physics Unit 3 content point on charged particles in uniform fields. The field between parallel plates, the constant force on a charge, energy gained through a potential difference, and parabolic deflection like a projectile.

A focused answer to the WACE Year 12 Physics Unit 3 content point on Coulomb's law. The inverse-square electrostatic force, attraction and repulsion of point charges, comparison with gravitation, and adding forces from several charges as vectors.

A focused answer to the WACE Year 12 Physics Unit 3 dot point on electric fields and potential. Coulomb's law, field strength for point charges and parallel plates, work, potential difference and the motion of a charge in a uniform field.

A focused answer to the WACE Year 12 Physics Unit 3 dot point on electromagnetic induction. Magnetic flux, Faraday's law, Lenz's law, induced emf, and the operation of AC generators and transformers.

A focused answer to the WACE Year 12 Physics Unit 3 dot point on gravitation and orbital motion. Newton's law of gravitation, gravitational field strength, projectile and circular motion, and deriving orbital speed and Kepler's third law for satellites.

A focused answer to the WACE Year 12 Physics Unit 3 content point on gravitational fields and energy. Field strength as force per unit mass, field-line representation, near-surface and changing potential energy, and the work done moving a mass in a field.

A focused answer to the WACE Year 12 Physics Unit 3 content point on the motor effect. The force on a current-carrying wire, the right-hand rule for direction, the torque on a current loop, and how a DC motor produces continuous rotation.

A focused answer to the WACE Year 12 Physics Unit 3 dot point on magnetism and moving charges. The force on a moving charge and a current-carrying conductor, the right-hand rule, circular motion in a field and the motor effect.

A focused answer to the WACE Year 12 Physics Unit 3 content point on Newton's law of universal gravitation. The inverse-square force law, the gravitational constant, treating bodies as point masses, and how surface gravity relates to mass and radius.

A focused answer to the WACE Year 12 Physics Unit 3 content point on projectile motion. Resolving velocity into components, applying constant horizontal velocity and constant vertical acceleration, and finding range, time of flight and maximum height.

A focused answer to the WACE Year 12 Physics Unit 3 content point on satellites and orbits. Gravity as the centripetal force, deriving orbital speed and period, Kepler's third law, and the special case of geostationary satellites.

A focused answer to the WACE Year 12 Physics Unit 3 content point on transformers and the grid. The turns-ratio equation, ideal power conservation, why transformers need AC, and why transmitting at high voltage cuts resistive line losses.

A focused answer to the WACE Year 12 Physics Unit 3 content point on uniform circular motion. Centripetal acceleration and force, horizontal circles, banked tracks and vertical circles, and identifying which real force supplies the centripetal requirement.