EE1F24-Dynamics Flashcards
(25 cards)
What are the basic parameters of a dynamic system?
Movement/displacement. Velocity. Speed. Acceleration.
What is displacement/movement?
Movement is the distance travel by an object, displacement is the distance from a starting point to an end point.
What is velocity?
Rate of change of displacement with respect to time.
What is speed?
Scalar equivalent of velocity.
What is acceleration?
Rate of change of velocity,
What are the equations of angular motion?
π = 1/2 (π0 + π1)t
π = π0π‘ + 1/2 πΌπ‘^2
π1^2 = π0^2 + 2πΌπ
What are the requirements for a body to be free to move?
-A force will make it accelerate in the direction of the force
-The amount of acceleration will depend on the bodyβs inertia (mass)
What is Newtons 1st law?
A body at rest will remain at rest or in uniform motion unless acted on by an external force.
What is Newtons 2nd Law?
The net force on an object is equal to the mass of an object multiplied by the acceleration.
How does the second law relate to angular acceleration?
T=Ia
T- Torque (Nm)
a- angular acceleration (radians/s^2)
I- Mass Moment of inertia
What is mass moment of inertia?
The mass moment of inertia quantifies the distribution of mass in a body relative to an axis of rotation.
What is newtons 3rd law?
Every action has an equal and opposite reaction.
What is friction?
An external force applied that always acts to resist motion.
What is Work?
If force F is to move a body through distance d then work is done.
What is radius of gyration?
The radius of gyration denoted as k is a theoretical distance from an axis at which the entire mass of a body could be collapsed to a single point such that to still have the same moment of inertia.
E.g if a cylinder was spinning its mass is distributed throughout the cylinder if we instead pictured all this mass as a point mass k is the length of a weightless supported we would have to attach this point mass for spinning to give the same moment of inertia.
What is moment of inertia?
The moment of inertia is the torque needed to rotate an object about an axis.
I=mk^2
What is the moment of inertia for a solid and thin walled cylinder?
(π = π/(2)^1/2 ) πΌ = 1/2 ππ^2 -Solid
(k=r) I=mr^2 -Thin
What is the moment inertia of a composite rotor?
For a composite rotor the moment of inertia is equal to the sum of moments of inertia of each of individual component.
What is the equation for work done by a rotating body?
W=Tπ
Where:
W= work done
T= Torque
π= Angular displacement
What is the rotational kinetic energy in a flywheel?
KE=1/2Iπ^2
Where:
I=mk^2
What is the coefficient of fluctuation of energy?
The coefficient of fluctuation of energy quantifies how much the kinetic energy of a rotating system fluctuates during a complete cycle of motion.
What is the equation of coefficient of fluctuation of energy?
Ce=(Emax-Emin)/(Emean)
Emax= Maximum kinetic energy of cycle
Emin= Minimum kinetic energy of cycle
Emean= Mean kinetic energy of cycle
What is the work done equation for coefficient of fluctuation of energy?
Ce=Greatest fluctuation of energy per cycle/work done per cycle
What is the maximum fluctuation of energy per cycle?
π½π=πΌβ
ππ^2
Where:
π2 β π1 = β
ππ
