Chapter 7: Angular Kinematics
Glossary
7.0 Introduction
- uniform circular motion
- the motion of an object in a circular path at constant speed
7.1 Rotation Angle and Angular Velocity
- arc length
- [latex]\text{Δ}s[/latex], the distance traveled by an object along a circular path
- pit
- a tiny indentation on the spiral track moulded into the top of the polycarbonate layer of CD
- rotation angle
- the ratio of the arc length to the radius of curvature on a circular path:
[latex]\text{Δ}\theta =\frac{\text{Δ}s}{r}[/latex]
- radius of curvature
- radius of a circular path
- radians
- a unit of angle measurement
- angular velocity
- [latex]\omega[/latex], the rate of change of the angle with which an object moves on a circular path
7.2 Angular Acceleration
- angular acceleration
- the rate of change of angular velocity with time
- change in angular velocity
- the difference between final and initial values of angular velocity
- tangential acceleration
- the acceleration in a direction tangent to the circle at the point of interest in circular motion
7.3 Centripetal Acceleration
- centripetal acceleration
- the acceleration of an object moving in a circle, directed toward the center
- ultracentrifuge
- a centrifuge optimized for spinning a rotor at very high speeds
7.4 Centripetal Force
- centripetal force
- any net force causing uniform circular motion
- ideal banking
- the sloping of a curve in a road, where the angle of the slope allows the vehicle to negotiate the curve at a certain speed without the aid of friction between the tires and the road; the net external force on the vehicle equals the horizontal centripetal force in the absence of friction
- ideal speed
- the maximum safe speed at which a vehicle can turn on a curve without the aid of friction between the tire and the road
- ideal angle
- the angle at which a car can turn safely on a steep curve, which is in proportion to the ideal speed
- banked curve
- the curve in a road that is sloping in a manner that helps a vehicle negotiate the curve
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7.5 Relating Angular and Translational Quantities
- total linear acceleration
- vector sum of the centripetal acceleration vector and the tangential acceleration vector
7.6 Fictitious Forces and Non-inertial Frames: The Coriolis Force
- fictitious force
- a force having no physical origin
- centrifugal force
- a fictitious force that tends to throw an object off when the object is rotating in a non-inertial frame of reference
- Coriolis force
- the fictitious force causing the apparent deflection of moving objects when viewed in a rotating frame of reference
- non-inertial frame of reference
- an accelerated frame of reference
7.7 Kinematics of Rotational Motion
- kinematics of rotational motion
- describes the relationships among rotation angle, angular velocity, angular acceleration, and time