ch.14 terms Flashcards
angular impulse
change in angular momentum equal to the product of torque and the time interval over which the torque acts
angular momentum
quantity of angular motion possessed by a body; measured as the product of moment of inertia and angular velocity
centripetal force
force directed toward the center of rotation for a body in rotational motion
moment of inertia
inertial property for rotating bodies representing resistance to angular acceleration; based on both mass and the distance the mass is distributed from the axis of rotation
principal axes
three mutually perpendicular axes passing through the total-body center of gravity
principal moment of inertia
total-body moment of inertia relative to one of the principal axes
radius of gyration
distance from the axis of rotation to a point where the body’s mass could be concentrated without altering its rotational characteristics
T/F: if an object’s mass or angular velocity increases, its angular momentum decreases
false
T/F: an extended body configuration produces greater angular velocity than a tuck position
false
angular impulse is the product of __ and __
torque and time
T/F: according to the principle of conservation of angular momentum, the total angular momentum of a given system remains constant in the absence of external torques
true
T/F: when angular momentum is conserved, changes in the body configuration produce a trade-off between moment of inertia and angular velocity
true
what variables contribute to the moment of inertia (I)?
mass (m) and radius of gyration (k)
T/F: an angular impulse can be used to produce a change in angular momentum
true
what is referred to as the “quantity of angular motion” possessed by a body?
angular momentum
If a diver goes from a full layout position to a tuck position, what will happen to their angular velocity?
their angular velocity will increase
Torque is the angular analogue of which linear quantity?
force
Torque is the angular analogue of which linear quantity?
force
what is a unit of I (I=moment of inertia)
kg*m^2
in the angular analogues of newtons laws, what is the angular equivalent of mass?
moment of inertia
T/F: the angular analogue of newtons 2nd law can be stated algebraically as T=Ia
true
according to newtons angular law of acceleration, a net torque produces angular acceleration of a body that is:
1.) directly proportional to the magnitude of the torque
2.) inversely proportional to the body’s moment of inertia
3.) in the same direction as the torque
what can be a unit of k (radius of gyration)
m
torque can be calculated as T=Fd(perpendicular)
true
the statement “a rotating body will remain a state of constant angular motion unless acted on by an external torque” refers to
newtons 1st law of inertia
what is a symbol for angular momentum
H
what is equivalent to T=Ia
Fd(perp)= mk^2a
the statement “for every torque exerted by one body on another, there is an equal and opposite torque exerted by the 2nd body on the 1st” is the angular analogue of newtons 2nd law
false
