Physics 2 Chapter 11

Oscillation

Object moving back and forth at fixed point

Equilibrium point

Point where sum of all forces = zero, spring is neutral

Hooke'S law

F=-kx

Simple harmonic motion

Type of oscillation motion where repeated oscillations occur over same time interval

The net restoring force causing oscillation is proportional to the negative of displacement

Amplitude

Maximum displacement during oscillation

Period

T. Time it takes to complete one cycle

Frequency

Cycles per second,f

Angular frequency

Measure of notational or oscillatory speed, how fast an object completes cycles

Sin vs cos starting

Sin functions represent when oscillation starts at equilibrium point while cos functions represent when oscillation starts at amplitude

Why can't work equation be used for SHM

The equation only works for constant force

Restoring force

A net force that proportionally acts to bring displaced object back to eq point

Energy in a spring

Fluctuates

Potential energy highest at amplitudes

Kinetic energy highest at equilibrium point

Waves

Generated when a disturbance is created in a system of equilibrium and the system transports energy

Mechanical wave

Needs medium to travel through ( sound, )

Non mechanical waves

Don't need medium to travel through ( light, radio)

Transverse waves

Cause vibrations perpendicular to disturbance (water, string)

Longitudinal waves

Cause vibration parallel to direction of wave propagation

Wavelength

Distance between 2 points of equal disturbance in wave

Amplitude

Max displacement of wave

Wave velocity

Wavelength x frequency

Young's modulus

E, measures material stiffness; tensile stress to tensile strain

Waves transport

Energy, not matter

Wave intensity

I, energy passing through area perpendicular to flow of energy

Wave front

Continuous boundary connecting all points in same phase

Incidence ray

Incoming beam that strikes surface and either reflects, refracts, etc

Standing wave

Wave oscillation that remains in a fixed position

Constructive interference

Waves cross and their amplitudes add

Destructive interference

Waves cross and their amplitudes cancel out

Antinode

Point on standing wave at max amplitude

Node

Point on standing wave with zero amplitude

First harmonic

Fundamental frequency , 1 antinode

2nd harmonic

1st overtone, 2 antinodes