Waves & Vibrations

Acoustics is

the branch of physics concerned with the study of sound

Acoustics deals with

production, transmission, reception, and effects of sound waves

What is sound?

a particle vibration within an elastic medium. What we hear

What are transverse waves?

particles in the medium move perpendicular to the direction in which the wave travels

What are longitudinal waves?

waves in which the particles move parallel to the direction in which the wave travels

A mechanical mode where a mass is attached to a spring, allowing it to oscillate and demonstrate simple harmonic motion

Mass-spring system

What is compression?

particles closer together than at rest

What is rarefaction?

particles farther apart than at rest

Are sound waves Transverse waves?

no

What is vibration?

the back-and-forth motion of an object or particle around an equilibrium point (or the point at which it would rest because all forces are in balance)

What causes waves?

1). Starting force (changes the state of motion)

2). Inertia/mass

3). Elasticity/stiffness

What is Inertia?

A fundamental property of all matter. The resistance an object has to a change in its state of motion

What is Newton’s first law?

An object at rest stays at rest and an object in motion stays in motion

What is mass?

A quantitative measure of inertia. The resistance that a body of matter offers to a change in speed or position upon application of a force

What is Elasticity?

the ability of the object or particle to return to its starting position (or shape) after the forces deforming them have been removed

In vibrating systems, the most common restoring forces are

1). Elasticity

2). Gravity

What is restoring force?

returns to object to resting position (equilibrium point)