SACE Physics — Stage 2
Circular Motion — Flashcards & Quiz
Uniform circular motion describes an object moving in a circle at constant speed with acceleration directed toward the centre. SACE Physics Stage 2 asks you to identify the real force providing the centripetal contribution in each scenario (tension, gravity, friction, normal component) and apply F_c = mv²/r. Banked tracks and satellite orbits are standard application contexts.
Sample Flashcards
Q1: Define uniform circular motion and derive centripetal acceleration.
Motion in a circle at constant speed. Velocity changes direction continuously, producing centripetal acceleration a_c = v²/r directed toward the centre. Also: a_c = ω²r = 4π²r/T².
Q2: What provides the centripetal force in common circular motion scenarios?
Centripetal force F_c = mv²/r is not a new force — it is the net inward force. Examples: gravity (orbits), tension (string), friction (car turning), normal force (banked track), gravitational + normal (roller coaster).
Sample Quiz Questions
Q1: In uniform circular motion, the net force is directed toward the centre of the circle.
Answer: TRUE
The centripetal force (net inward force) maintains circular motion by continuously changing the velocity direction.
Q2: Doubling the speed in circular motion doubles the centripetal force required.
Answer: FALSE
F_c = mv²/r — centripetal force is proportional to v². Doubling speed quadruples F_c.
Last updated: March 2026 · 2 flashcards · 2 quiz questions