Circular Motion Flashcards
Define Circular Motion
Motion that is resulted from a net force perpendicular to the direction of motion
Angular Speed
The rate of change in angular displacement with respect to time
Linear speed
The rate of change of linear displacement with respect to time when motion is in a straight path
Angular displacement
The change of angle as it rotates
Tangential speed
The speed of an object moving along the circumference of a circular path
Radian
The angle subtended at the centre of a circle by an arc equal in length to the radius of the circle
Why does the speed of an object in circular motion not change?
The net force is directed perpendicular to the
Direction of motion (the velocity), this means that there is no work done by this force
W=F x cosX cos90=0
What are the conditions of uniform centripetal force?
- Has to be perpendicular to velocity
- Has to have constant velocity
What is rotational system and linear(translational) system and what is considered circular motion?
1.rotational system rotates about an axis through the system
2.linear system moves about an axis outside the system
3.rotational system describe path of C.M in terms of angles and looks at the motion from centre
What are the changes quantities in the four equations?
S = angle
V = angular velocity
A = angular acceleration
Centripetal Acceleration
Caused by a centripetal force of constant magnitude
That also acts perpendicular to the direction of motion in the centre
Oscillation
A repeated back and forth movement on either side of some equilibrium position
-when object stopped it will return to equilibrium
Forced oscillation properties
1.constantly applied force
2.frequency depends of force
free oscillation
1.requires force to initiate only
2.frequency only depends on the nature of oscillation(natural frequency)
Frequency
Number of oscillations in unit time
Phase
The point that an oscillating mass has reached within one complete cycle
What are properties of simple harmonic motion
1.the magnitude of acceleration and displacement are proportional to one another
2.the directions of acceleration and displacement are opposite to one another
3.period and amplitude are constant
4.period/frequency is independent of amplitude
5.displacement, velocity and acceleration are all sinusoidal functions in time
6.mass that oscillates and a position where it is equilibrium
7.have a restoring force that acts to return mass to equilibrium
Force field
Region in the space where mass/charge/magnet pole experiences force
Radial field
Field lines converge towards the centre of mass
Newton’s universal law of gravitation
Force between two point masses is directly proportional to the product of the two masses and inversely proportional to square of the separation of the masses
Field strength
Force experienced by a unit mass at a given point
Gravitational potential energy
GPE of a mass at a point is the amount of work done in bringing the mass from infinity
Gravitational potential
The GP at a point is the work done to bring a unit mass from infinity
Damping
When oscillating system loses energy to the surrounding which results in decreasing amplitude
Critical damping
The condition in which the damping of an oscillator causes it to return as quickly as possible to its equilibrium position without oscillating back and forth about this position
Over damping
The condition in which damping of an oscillator causes it to return to equilibrium without oscillating; oscillator moves more slowly toward equilibrium than in the critically damped system
Under damping
The condition in which damping of an oscillator causes it to return to equilibrium with the amplitude gradually decreasing to zero; system returns to equilibrium faster but overshoots and crosses the equilibrium faster but overshoots and crosses the equilibrium position one or more times
Resonance
A phenomenon in which frequency of externally applied periodic force equals the natural frequency of the system, resulting in oscillation in largest possible amplitude
What are some advantages of resonance
- Microwave-resonating water molecules with EM wave at freq of natural freq of H20
2.MRI(magnetic resonance Imaging)
What are some disadvantages of resonance
Earthquakes resonating buildings
What happens to resonance graph during damping?
-overall amplitude will decrease, curve below original
-Net gain of energy is less, flatter peak
-resonance frequency decreases, shifted peak to the left
Simple harmonic motion
Acceleration proportional to displacement and directed towards a fixed point
Natural frequency
The unforced frequency of oscillation of a freely oscillating object
