Year 2 Chapter 2: Simple Harmonic Motion Flashcards
What is simple harmonic motion?
Motion where the acceleration of an object is directly proportional, and in the opposite direction, to its displacement
What are some key features of simple harmonic motion?
-Object oscillates either side of an equilibrium position
-Restoring force acts towards equilibrium position
-Force is proportional to its displacement (F= -kx)
-so acceleration is proportional to displacement
What is the defining equation for SHM?
F= -kx
F: force
k: constant
x: displacement
- shows its in opposite direction to displacement
What are spring oscillators and what is the period unaffected by?
A mass on a spring that oscillates with SHM. Not affected by gravitational field strength or initial displacement
What are pendulum oscillators and what is the period unaffected by?
A mass on a string that oscillates with SHM. Not affected by bob’s mass or initial displacement
Describe the energy stores of the objects at either end of the oscillation
Velocity is zero, so Ek is zero
Potential energy is at a maximum
Total energy is the same throughout
Describe the energy stores of the object at its equilibrium position
Velocity is at its maximum, so Ek is at a maximum
Potential energy is at a minimum at 0
Total energy is the same throughout
How do the energy stores of an object in SHM vary throughout without damping
Kinetic + potential energy = total energy
This is constant and there are two maximum Ek and Ep per cycle
What is damping and what causes it?
The dissipation of energy from an oscillating system. It causes the amplitude of oscillation to decrease. Damping occurs when a force opposes the system’s motion, eg friction or air resistance
What are some examples of deliberate damping?
Car suspension systems, springed doors, speedometer dials, swings
What is light damping?
A type of damping where energy is gradually removed from the system and the amplitude of oscillations slowly decreases
What is critical damping?
The minimal amount of damping that stops the oscillations in the quickest time possible.
What is heavy damping?
When the system is damped more than required to stop the oscillations. It takes longer for the system to return to equilibrium than for critical damping.
What are free vibrations?
Oscillations that are not caused by a driver. An object will naturally oscillate at its natural frequency.
What are forced vibrations?
Oscillations caused by a driving force, they oscillate at the driving frequency. The amplitude of oscillation is small at high frequencies and large at low frequencies.
