AP Physics Waves & Optics

Question 1

What is the definition of a wave?

Accepted Answer

A transfer of energy without matter movement

Answer

A wave is fundamentally a disturbance that propagates through a medium or space, transferring energy from one point to another. Crucially, this transfer of energy occurs without the net transfer of matter; the particles of the medium oscillate about their equilibrium positions but do not travel along with the wave itself.

Question 2

What is the relationship between frequency and wavelength in a wave?

Accepted Answer

Frequency is inversely proportional to wavelength

Answer

For a wave traveling at a constant speed (v), its frequency (f) and wavelength (λ) are inversely proportional, as described by the wave equation v = fλ. This means that if the frequency of a wave increases, its wavelength must decrease, and vice versa, to maintain a constant wave speed.

Question 3

What is refraction?

Accepted Answer

Bending of light due to density change

Answer

Refraction is the phenomenon where a wave, such as light, changes direction as it passes from one medium to another. This bending occurs because the wave's speed changes as it enters a medium with a different optical density, causing it to deviate from its original path according to Snell's Law.

Question 4

What is the main principle behind the Doppler effect?

Accepted Answer

Wave frequency changes due to relative motion

Answer

The Doppler effect describes the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. When the source and observer move closer, the frequency appears higher, and when they move apart, the frequency appears lower, due to the compression or stretching of the wavefronts.

Question 5

What does the law of reflection state?

Accepted Answer

Angle of incidence equals angle of reflection

Answer

The law of reflection states that when a wave, such as light, strikes a surface, the angle at which it hits the surface (angle of incidence) is equal to the angle at which it bounces off (angle of reflection). Both angles are measured with respect to the normal, an imaginary line perpendicular to the surface.

AP Practice Test

AP Practice Test

AP Physics Waves & Optics