Rotational Kinematics
🔁 CORE IDEA (anchor this first)
v = r\omega
Flashcard 1
Q: What is the core link between rotational and linear motion?
A: Linear motion is just rotation seen at a distance from the center. The farther out you are, the faster you move.
🧠 VISUAL FOUNDATION
Flashcard 2
Q: What is angular position (θ)?
A: How far something has rotated, like how much of a circle you’ve swept through (in radians).
Flashcard 3
Q: What is angular displacement?
A: The change in rotation — imagine turning a steering wheel from left to right.
Flashcard 4
Q: What is angular velocity (ω)?
A: How fast something spins — like how fast a fan blade rotates.
Flashcard 5
Q: What is angular acceleration (α)?
A: How quickly the spinning speed is changing — like a fan speeding up.
🔄 ROTATION vs STRAIGHT LINE (CRITICAL CONNECTIONS)
a_t = r\alpha
Flashcard 6
Q: What is the rotational version of position (x)?
A: Angular position (θ)
Flashcard 7
Q: What is the rotational version of velocity (v)?
A: Angular velocity (ω)
Flashcard 8
Q: What is the rotational version of acceleration (a)?
A: Angular acceleration (α)
Flashcard 9
Q: What does v = r\omega actually mean physically?
A: Points farther from the center move faster, even though everything rotates together.
Flashcard 10
Q: What does a_t = r\alpha represent?
A: How fast the speed along the circle is changing.
🎯 CENTRIPETAL MOTION (TEST FAVORITE)
a_c = \frac{v^2}{r}
Flashcard 11
Q: What is centripetal acceleration?
A: Acceleration pointing toward the center that keeps something moving in a circle.
Flashcard 12
Q: Why do you feel pulled outward on a ride?
A: Your body wants to move straight, but the force pulls you inward → feels like outward push.
Flashcard 13
Q: What direction is centripetal acceleration always?
A: Toward the center of the circle.
🧮 ROTATIONAL KINEMATICS EQUATIONS (LIKE LINEAR)
\omega_f = \omega_i + \alpha t
\theta = \omega_i t + \frac{1}{2}\alpha t^2
Flashcard 14
Q: What’s the rotational version of v = v_0 + at?
A: Same idea, but with angular quantities.
Flashcard 15
Q: What’s the rotational version of displacement equation?
A: Same structure as linear, just replace x with θ.
Flashcard 16
Q: What’s the biggest mistake students make here?
A: Mixing up linear and angular variables.
⚙ “WHAT AM I ACTUALLY DOING?” CARDS (MENTAL IMAGES)
Flashcard 17
Q: What am I doing when I calculate angular velocity?
A: Measuring how fast something spins around a center.
Flashcard 18
Q: What am I doing when I use v = r\omega?
A: Converting spinning motion into straight-line speed.
Flashcard 19
Q: What am I doing when I calculate centripetal acceleration?
A: Finding how hard something is being pulled inward to stay in a circle.
Flashcard 20
Q: What am I doing when I use angular acceleration?
A: Tracking how quickly the spin speed is changing.
🧩 KEY INSIGHT CARDS (HIGH LEVEL UNDERSTANDING)
Flashcard 21
Q: Why do all points on a rotating object have the same ω?
A: They complete each rotation together.
Flashcard 22
Q: Why do outer points move faster?
A: They travel a larger circle in the same time.
Flashcard 23
Q: What happens if radius increases?
A: Linear speed increases, angular speed stays the same.
⚡ QUICK CHECK CARDS (TEST SPEED)
Flashcard 24
Q: Units of angular velocity?
A: rad/s
Flashcard 25
Q: Units of angular acceleration?
A: rad/s²
Flashcard 26
Q: Units of θ?
A: radians
🧠 FINAL MASTER VISUAL
Flashcard 27
Q: How should I picture all of rotational motion?
A:
A spinning wheel:
Center = slow (almost no movement)
Edge = fastest
Everything rotates together but moves differently