Term

Definition
an extended line drawn collinear with the force 


Term

Definition
the distance "l" between the line of action & the axis of rotation, measured on a line that is perpendicular to both 


Term
What is the direction of torque? 

Definition
the torque "tau" is positive when the force tends to produce a counterclockwise rotation about the axis, & negative when the force tends to produce a clockwise rotation 


Term

Definition


Term
Can the same magnitude produce different torques? 

Definition


Term

Definition
forces from external agents; the only forces used when calculating the net force 


Term
When is a rigid body in equilibrium? 

Definition
if it has zero translational acceleration & zero angular acceleration; the sum of the externally applied forces is zero & the sum of the externally applied torques is zero 


Term
Why is the choice of axis arbitrary in equilibrium? 

Definition
if an object is in equilibrium, it is in equilibrium with respect to any axis whatsoever 


Term

Definition
a definite point chosen at which the weight acts on an object for the purpose of calculating the torque 


Term
Where does the center of gravity lie for any symmetrically shaped & uniform object? 

Definition
at its geometrical center 


Term
SI unit of moment of inertia 

Definition


Term
What requirement must be met in order to use the rotational analog of Newton's second law for a rigid body rotating about a fixed axis (sum of the torques = moment of inertia x angular acceleration) 

Definition
alpha must be expressed in rad/s^2 


Term

Definition
the distances that locate each particle do not change during the rotational motion 


Term
When calculating the sum of the torques, it is necessary to include only the _____, those applied by agents outside the body 

Definition


Term
What requirement must be met to determine rotational work (rotational work = constant torque x angle) 

Definition
theta must be expressed in radians 


Term
SI unit of rotational work 

Definition


Term
What requirement must be met to determine to rotational kinetic energy (rotational kinetic energy = 1/2(moment of inertia x angular speed^2)) 

Definition
omega must be expressed in rad/s 


Term
SI unit of rotational kinetic energy 

Definition


Term
What is the analogous concept to linear momentum in terms of rotational motion? 

Definition


Term
What requirement must be met to determine the angular momentum (angular momentum = moment of inertia x angular velocity) 

Definition
omega must be expressed in rad/s 


Term
SI unit of angular momentum 

Definition


Term
principle of conservation of angular momentum 

Definition
the total angular momentum of a system remains constant if the net average external torque acting on the system is zero; total angular momentum of a system is conserved 

