HW 1-16

CH. 25 WAVES

Ch. 25.1-25.2•1

. A vibration causes a wave and a wave spreads out through space.

•2. The period would be 1 second.

•3. The pendulum would take 1.5 seconds.

•4. A longer period is produced by a longer pendulum

•5. A sine curve represents the periodic motion of a wave and demonstrates simple harmonic motion of the particles that transmit the wave energy.

Ch. 25•6

. Parts of a wave•Amplitude equals the maximum displacement from the point of equilibrium

•Crest is the high point on a wave•Trough is the low point on a wave•Wavelength is the distance from one point to the next identical point on a wave

7. Period is the time it takes for one complete cycle of a wave (seconds); the frequency is the number of waves that pass a single point per unit time or the number of vibrations per second (Hertz)

Ch. 25•8

. No. The medium does not move along with the wave. The wave energy passes through the medium and is carried by the disturbance that travels through.

•9. The speed of a wave is calculated by multiplying frequency by wavelength.

•10. As the frequency of a sound increases, the wavelength decreases (inverse relationship)

Ch. 25•1

1. Difference between transverse and longitudinal waves•A transverse wave is produced by a vibration that is perpendicular to wave travel.

•A longitudinal wave is produced by a vibration that occurs parallel to or is in the same direction as wave travel.

Ch. 25•1

2. Wave interference occurs when two or more waves share the same space and the amplitude of the wave either increases or decreases.•Constructive interference: when the interference of two or more waves produce a wave with a larger amplitude

•Destructive interference: when the interference of two or more waves produce a wave with a smaller amplitude (sometimes the waves will completely cancel each other out)

•13. Interference is a property shared by all types of waves.

Ch. 25•1

4. A standing wave is a wave that appears to stay in one place. A standing wave forms when two waves identical in frequency, wavelength and amplitude moving in opposite directions interfere (incident and reflected waves)

•Antinodes form by constructive interference (waves build in phase) and nodes form by destructive interference (waves cancel out completely and are out-of-phase)

Ch. 25•1

5. The Doppler Effect is an apparent shift in frequency caused by the motion of a source of a wave relative to an observer or vice-versa. As the source of a wave approaches a receiver, the receiver will encounter only an increase in wave frequency.

•16. The Doppler Effect occurs for all waves, but is most recognizable for sound waves and light waves.

The Parts of a WaveA weight attached to a spring undergoes simple harmonic motion.

A marking pen attached to the bob traces a sine curve on a sheet of paper that is moving horizontally at constant speed.

A sine curve is a pictorial representation of a wave.

25.2 Wave Description