Chapter 7
Circular Motion
Separate the direction of motion from the direction of acceleration, then choose the actual forces and the correct radius.
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Describe a turn
Use radians, period and frequency to connect angular and tangential speeds, and measure repeated turns.
Why acceleration points inward
Construct a change of velocity and distinguish a finite-interval average from instantaneous inward acceleration.
Choose the radial force
Resolve actual forces in a tether and conical pendulum, and interpret force-speed data.
Gravity and the near-Earth field
Use centre separation in Newtonian gravitation and explain why near-surface field strength is approximately constant.
Circular orbits and geostationary satellites
Use gravity as the inward resultant, distinguish altitude from radius and explain the conditions for a fixed apparent position.