ch 9

Question 1

arc length

Answer 1

Δs, the distance traveled by an object along a circular path

Question 2

rotation angle

Answer 2

the ratio of the arc length to the radius of curvature on a circular path:
Δ
θ
=
Δ
s
r

Question 3

angular velocity

Answer 3

ω, the rate of change of the angle with which an object moves on a circular path

Question 4

angular acceleration

Answer 4

the rate of change of angular velocity with time

alpha = w / dlta t

Question 5

change in angular velocity

Answer 5

the difference between final and initial values of angular velocity

Question 6

tangential acceleration

Answer 6

the acceleration in a direction tangent to the circle at the point of interest in circular motion

Question 7

kinematics of rotational motion

Answer 7

describes the relationships among rotation angle, angular velocity, angular acceleration, and time

Question 8

rotational inertia

Answer 8

resistance to change of rotation. The more rotational inertia an object has, the harder it is to rotate
moment of inertia
mass times the square of perpendicular distance from the rotation axis; for a point mass, it is I = mr2 and, because any object can be built up from a collection of point masses, this relationship is the basis for all other moments of inertia

Question 9

centripetal acceleration

Answer 9

, the acceleration of a body traversing a circular path.

Question 10

angular position

Answer 10

represents the orientation of a line with another line or plane

Question 11

angular position

Answer 11

represents the orientation of a line with another line or plane

Question 12

angular displacement

Answer 12

of a body is the angle through which a point revolves around a centre or a specified axis in a specified sense.

Question 13

Period

Answer 13

the time for a particle on a medium to make one complete cycle or revolution (measured in seconds, minutes etc..)

Question 14

rotational frequency

Answer 14

the number of revolutions per second

Question 15

revolutions

Answer 15

the number of turns in one minute. It is a unit of rotational speed or the frequency of rotation around a fixed axis.

Question 16

angular frequency

Answer 16

the number of radians per second

Question 17

moment of inertia

Answer 17

the tendency of an object to resist change in motion

Question 18

rotational dynamics

Answer 18

the study of forces and motions about an axis of rotation.

Question 19

Newton’s second law of rotation

Answer 19

If more than one torque acts on a rigid body about a fixed axis, then the sum of the torques equals the moment of inertia times the angular acceleration:

Question 20

rotational kinetic energy

Answer 20

kinetic energy due to the rotation of an object

Question 21

rolling motion

Answer 21

Rolling motion is that common combination of rotational and translational motion