Oscillations Flashcards
What is a restoring force?
The force that brings the object back to its equilibrium position
What is a driving force?
The driving force puts energy into the system at a certain frequency
What is the definition of simple harmonic motion (SMH)?
An object experiencing SMH is one which experiences a restoring force which acts towards the centre of equilibrium. Here the force is directly proportional to the distance from the equilibrium position
What is the restoring force in a simple pendulum?
Gravity (g)
What is the equation that shows SMH?
F=-kx
What equation can you use to find the time period in a simple pendulum?
T=2π√l/g
What is the equation you can use to find the time period for a mass-spring system?
T=2π√m/k
Where k is the spring constant
What graph does the displacement-time graph resemble?
The sin graph
What graph does the velocity-time graph resemble?
The cosine graph
What is the gradient on the displacement-time graph?
Velocity
What is the gradient on a given point on the graph?
Acceleration
What is resonance?
Resonance is when the amplitude of oscillations increases drastically due to the gaining an increased amount of energy from the driving force
Why does resonance occur?
Resonance occurs when the driving frequency is equal to the natural frequency of a system (all systems have a unique natural frequency)
What is the natural frequency of a system?
This is what the system oscillates at when no external force is applied
What is a forced vibration?
When the system has a external driving force applied to it causing it to oscillate
What is a free vibration?
When the system oscillates at its natural frequency
What is damping used for?
To decrease the effects of resonance
What is damping?
When a force acts on an oscillating system and energy is lost from the system to it’s environment, therefore decreasing the amplitude
What are the three main types of damping?
Light damping- when the amplitude decreases gradually with each oscillation
Critical damping- bringing the amplitude down to 0 ASAP
Heavy damping- critical damping but slower
How can the plastic deformation of a ductile material be used for damping?
Ductile materials can undergo large amounts of plastic deformation before fracturing, energy can be used to deform the material which decreases the KE which reduces the amplitude of oscillations
