Constant in Uniform Circular Motion Quiz
20 quick questions with instant feedback. See which quantity remains constant.
Editorial: Review CompletedUpdated Aug 26, 2025
This quiz helps you find what stays constant in uniform circular motion and what changes. Answer 20 quick questions to review speed, angular speed, velocity direction, and centripetal acceleration. For more practice, try the forces and motion quiz, check your skills with the speed and acceleration quiz, or refresh basics in a Newton's first law quiz.
Study Outcomes
- Understand the concept of uniform circular motion and its associated constant values.
- Identify the constant parameters in scenarios involving uniform circular motion.
- Apply formulas to calculate and validate constant values such as angular velocity.
- Analyze the relationship between angular speed and radius in a circular path.
- Evaluate self-assessment problems to reinforce the comprehension of constants in circular motion.
Uniform Circular Motion Constant Cheat Sheet
- Speed remains constant - In uniform circular motion, the object travels equal arcs in equal time slices, so the speed never wavers as it zooms around the circle. Picture a race car keeping a steady pace even as it hugs every bend.
- Tangential velocity direction changes - While the magnitude of tangential velocity stays the same, its head spins around constantly as the object orbits the center. Imagine the needle of a spinning compass always pointing sideways to keep you on track.
- Centripetal acceleration points inward - This acceleration always aims at the circle's center and has magnitude ac=v²/r, linking how fast you go to how tight the curve is. It's like the invisible hand steering a satellite around Earth.
- Centripetal force keeps you turning - The net force pulling you inward equals Fc=m·ac=m·v²/r, balancing mass, speed, and curve radius. Whether it's tension in a string or friction on a tire, that force is your roundabout guide.
- Angular velocity is uniform - Denoted ω, this spin rate stays constant and links directly to linear speed via v=r·ω, tying together distance from center and how quickly you rotate. Think of RPM on your bike wheel!
- Period stays the same - The time T for one full loop never changes, and ω=2π/T ties rotation rate to how long each lap takes. It's like the beat of a metronome for circular motion.
- Frequency is constant - Revolutions per second f=1/T remain steady, measured in hertz (Hz). Think of it as the circular motion's "song," humming at a fixed pitch.
- Radius stays fixed - You keep the same distance from the center, so r never wiggles during the motion. Changing r would crank up or chill out your acceleration - so it's crucial to stay locked in.
- Net force magnitude is constant - All forces combine to give a steady inward pull equal to Fc, so you never get a surprise push or pull. It's the physics equivalent of cruise control in radial forces.
- Centripetal acceleration is always radial - Perpendicular to the path's tangent, this acceleration vector always points toward the center, making sure the object bends its path without speeding up or slowing down. Imagine an invisible leash keeping you on the circular track.