13. Oscillations Flashcards
What happens it an object is experiencing simple harmonic motion?
- It experiences a restoring force which acts towards the centre of equilibrium.
- Its force is directly proportional to the object’s distance from equilibrium.
What is amplitude?
The maximum displacement of an oscillating system
What is time period?
Time take for one full cycle of an oscillating system.
e.g.
Equilibrium to amplitude.
Then amplitude to equilibrium.
What is the restoring force?
A force that acts towards the equilibrium.
What is true about the acceleration of an object experiencing SHM?
It’s acceleration is directly proportional to is displacement and is in the opposite direction.
a = -ω²x
What is angular velocity?
The angle an objects moves through per unit time.
ω = 2πf
What effect the time period of these simple harmonic systems?
- Simple pendulum
- Mass-spring system
Simple pendulum: mass and length of spring.
- Mass-spring system:
mass and spring constant.
Describe the graph of displacement against time of a SHsystem.
Sinusoidal
- starting at (+)amplitude.
Describe the graph of velocity against time of a SHsystem.
Sinusoidal
- starting at 0
(its the gradient function of dis-time)
Describe the graph of acceleration against time of a SHsystem.
Sinusoidal
- starting at (-)amplitude.
(its the gradient function of velo-time)
What is resonence?
Where the amplitude of an oscillating system increases due to gaining an increased amount of energy from the driving force.
When does resonance occur?
When the driving force is equal to the natural frequency of the system.
How do you decrease the effects of resonance?
Dampening.
What is dampening?
- Where a force acts on an oscillating system and energy is lost from the system to its environment.
- Leading to a reduced amplitude.
When can oscillating systems lose/gain energy?
When an external force acts on it.