, What is the moment of inertia for an isolated point mass? - CORRECT ANSWERS-A
measure of how difficult it is to alter an object's rotational speed:
I = mr^2
I = moment of inertia (kg m^2)
m = mass (kg)
r = distance from axis of rotation (m)
What is the moment of inertia of an extended object? - CORRECT ANSWERS-I =
∑mr^2
Add the individual moments of inertia for each point mass that makes up the object.
if a small mass m is added to a rod at radius r from the axis of rotation, what is the new
moment of inertia? - CORRECT ANSWERS-I(new) = I(initial) + mr^2
Where mr^2 is the moment of inertia for the small mass added.
What affects the moment of inertia of a rotating object? - CORRECT ANSWERS-The
mass and mass distribution of the object, the position of the axis of rotation and how far
away the mass is from it.
What is the rotational kinetic energy of an object? - CORRECT ANSWERS-Ek =
0.5Iω^2
I is the moment of inertia (kg m^2) and ω is the angular speed (rad s^-1).
What is Torque? - CORRECT ANSWERS-a measure of how much a force acting on an
object causes that object to rotate about an axis. Measured in Newton meters (N m).
What is a flywheel? - CORRECT ANSWERS-Flywheels are heavy wheels with a high
moment of inertia and angular momentum that convert inputted torque to rotational
kinetic energy. They are used to store energy in a machine to be used at another point
in a system.
What factors affect the energy storage capacity of a flywheel? - CORRECT ANSWERS-
Shape and mass: Increased moment of Inertia, increased Ek. Flywheels shaped as
wheels instead of discs can store more energy as r is greater. Spoked wheels store
more energy.
Material: ωmax is restricted by the breaking stress of the flywheel, higher ωmax higher
Ek.
How are flywheels used for storing energy in braking vehicles? - CORRECT
ANSWERS-Electric vehicles use regenerative braking. When the brakes are applied, a
flywheel is engaged, which charges up with the energy being lost. The energy is used to
move the wheels when the behicle accelerates and is then disengaged.
How are flywheels used for smoothing torque and angular velocity? - CORRECT
ANSWERS-Flywheels use each burst of power to charge and then smoothly deliver the
energy to rotating components. For systems that exert a varying force when the load
measure of how difficult it is to alter an object's rotational speed:
I = mr^2
I = moment of inertia (kg m^2)
m = mass (kg)
r = distance from axis of rotation (m)
What is the moment of inertia of an extended object? - CORRECT ANSWERS-I =
∑mr^2
Add the individual moments of inertia for each point mass that makes up the object.
if a small mass m is added to a rod at radius r from the axis of rotation, what is the new
moment of inertia? - CORRECT ANSWERS-I(new) = I(initial) + mr^2
Where mr^2 is the moment of inertia for the small mass added.
What affects the moment of inertia of a rotating object? - CORRECT ANSWERS-The
mass and mass distribution of the object, the position of the axis of rotation and how far
away the mass is from it.
What is the rotational kinetic energy of an object? - CORRECT ANSWERS-Ek =
0.5Iω^2
I is the moment of inertia (kg m^2) and ω is the angular speed (rad s^-1).
What is Torque? - CORRECT ANSWERS-a measure of how much a force acting on an
object causes that object to rotate about an axis. Measured in Newton meters (N m).
What is a flywheel? - CORRECT ANSWERS-Flywheels are heavy wheels with a high
moment of inertia and angular momentum that convert inputted torque to rotational
kinetic energy. They are used to store energy in a machine to be used at another point
in a system.
What factors affect the energy storage capacity of a flywheel? - CORRECT ANSWERS-
Shape and mass: Increased moment of Inertia, increased Ek. Flywheels shaped as
wheels instead of discs can store more energy as r is greater. Spoked wheels store
more energy.
Material: ωmax is restricted by the breaking stress of the flywheel, higher ωmax higher
Ek.
How are flywheels used for storing energy in braking vehicles? - CORRECT
ANSWERS-Electric vehicles use regenerative braking. When the brakes are applied, a
flywheel is engaged, which charges up with the energy being lost. The energy is used to
move the wheels when the behicle accelerates and is then disengaged.
How are flywheels used for smoothing torque and angular velocity? - CORRECT
ANSWERS-Flywheels use each burst of power to charge and then smoothly deliver the
energy to rotating components. For systems that exert a varying force when the load
