SHM and Circular Motion Flashcards
Define time period (SHM)
Time for one complete oscillation
Define frequency (SHM)
The number of oscillations per unit time.
Define amplitude
The maximum displacement from the equilibrium position.
Define simple harmonic motion
An oscillation where acceleration is directly proportional to displacement but in the opposite direction.
Define damping
The removal of energy from an oscillating system. It is due to work done against resistive forces producing heat.
What changes due to damping?
Amplitude decreases
All types of energy decrease
Maximum velocity decreases
What stays the same during damping?
Time period and frequency.
When does a system oscillate at its natural frequency?
When there are no external driving forces acting in the system.
How do you create a driving frequency?
Use an external force to produce forced oscillations.
Define resonance
If the driving frequency is equal to the natural frequency then resonance occurs. There is maximum energy transfer and the system oscillates with maximum amplitude.
Define time period (Circular Motion)
Time for one complete orbit
Define frequency (circular motion)
The number of orbits per unit time.
Why does a mass undergoing circular motion have constant speed but accelerate?
Acceleration is the rate of change of velocity. Velocity is a vector and is always changing direction. This means that the mass accelerates.
What direction is the centripetal acceleration?
Towards the centre of the circle
Define centripetal force
A resultant force, at 90 degrees to the velocity, towards the centre of the circle.
Why is kinetic energy constant for a mass undergoing circular motion?
The centripetal force is at 90 degrees to the velocity, so there is no displacement in the direction of the force. This means no work is done so the mass has constant kinetic energy and constant speed.
What is the equation for Vmax?
Vmax = ωA
What is the equation for Amax?
Amax = Aω^2
What is the equation for energy of a system undergoing SHM?
Total energy = 1/2 mv^2 + mgh
Loss of KE = gain in PE
Alternative equation for V
V = 2πr / T
For x = Acosωt = Asinωt what is the angle measured in?
Radians
