Count angles beyond one turn
Distinguish repeated orientation from accumulated angular displacement. Use counterclockwise-positive angular quantities and separate angular distance from net angle through a reversal.
AP Physics 1 · Unit 5 · Rotation
Rotational Kinematics Practice Problems
Connect a rotor’s angular motion with the motion of points at different radii. Practice clock-hand rates, rpm conversions, start-up and braking, rim acceleration components, and latitude-circle speeds.
13 questions6 conceptual · 7 calculation
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What you’ll practice
Connect rotation with the path of a point
Convert rates and analyze changing rotation
Convert rev/min to rad/s, use period to find angular velocity, and apply constant-angular-acceleration equations to a rotor starting or stopping.
Find linear motion at a chosen radius
Use v = r|ω|, tangential acceleration rα, and inward radial acceleration rω². Resolve perpendicular acceleration components and use R cos(latitude) for a latitude circle.
A question from this set
Two points on one rigid rotor
Points A and B are fixed to the same rigid rotor, with B twice as far from the axis as A. Which quantities must be the same for the two points?
Try it in the practice setKey ideas
Every point shares the rotation; radius determines linear motion
One rigid rotor has one angular velocity
A point near the axle and a point on the rim sweep out the same angle over the same time. The outer point travels a longer arc, giving it a greater linear speed.
Zero angular acceleration can coexist with linear acceleration
At constant angular speed the rim point’s speed is steady, but its velocity changes direction. It still has inward radial acceleration. During spin-up, a tangential component also changes its speed.
See the physics
Inspect measured angles and point motion
After attempting the question, run a native rotating body. Compare angular displacement, angular velocity, and angular acceleration graphs. Use separate clock-hand trials, rotor comparisons, and slow-motion close-ups of start-up and stopping. The displayed physical seconds explain differences in playback rate.
Use a hint for a starting point or open a worked solution to follow the reasoning. Your progress saves in this browser, so you can return to unfinished questions.
Ready for rotational kinematics?
Begin with a conceptual question, then work through the calculations.