Energy and SHM Flashcards
What is a free oscillation?
When an object oscillates with constant amplitude and there are no frictional forces acting on it
What happens when a pendulum is freely oscillating?
The energy in the system stays constant
What does it mean if the motion is damped?
there are dissipative forces
What is underdamping?
When an object oscillates with SHM with a decreasing amplitude over time
What is critical damping?
When damping is large enough to stop the object and will reach the equilibrium point without overshooting in the quickest time
What is overdamping?
The damping is larger than the critical damping value, the object won’t oscillate but takes longer to reach equilibrium than the critical system
What are forced oscillations?
When a periodic force is applied to a system and causes it to have the frequency of the periodic force
What is resonance?
When the frequency of the periodic force matches the resonant frequency of the system causing an increase in amplitude.
What happens when the periodic force frequency is less than the natural frequency?
Phase difference is zero, increasing to π/2
What happens when the periodic force frequency is equal to the natural frequency?
Phase difference is π/2
What happens when the periodic force frequency is greater than the natural frequency?
Phase difference increases from π/2 to π
What happens when damping is increased?
- Peak amplitude decreases
- Resonance peak will be broadened
- Resonant frequency will be reduced
What is the equation for maximum displacement?
x= A cos (2πft)
What is the equation for zero displacement?
x= A sin(2πft)
What is the relationship between acceleration and displacement in SHM?
acceleration is proportional to displacement, the acceleration is in the opposite direction to displacement
What two things does the time period of a pendulum depend on?
length, and strength of gravity
What two things does the time period of a mass on a spring depend on?
mass and spring constant
What are the conditions of SHM?
Acceleration must be proportional to displacement from the equilibrium point, it must act towards the equilibrium point, a∝-x
What is the constant of proportionality connecting acceleration and x?
w^2 or -k/m
How can you calculate maximum speed?
max speed= wA
How do you calculate maximum acceleration using w and A?
max acceleration= w^2A
