1. Transverse waves carry molecules at right angles to the direction in which the wave travels. Within a cycle, molecules move from their normal position to the highest position, back through the normal position to the lowest point, and then back to the normal position. The molecules retain their horizontal positions while vibrating vertically. Amplitude is measured at right angles to the direction of the travel of the wave. Wavelength can be represented as the distance between any two molecules in phase with each other, such as the two nearest molecules at the crests of the wave.
Longitudinal waves carry molecules parallel to the direction in which the wave travels. Within a cycle, a molecule travels in the same direction as the wave (from normal position to its most distant point on one side of its normal position), changes direction, moves back through its normal position to the opposite side of its normal position at a point that corresponds, and then returns to its normal position. The molecules don’t all move at the same time; some remain stationary as others go through a vibrating motion. Compressions and rarefactions occur here. Amplitude is measured parallel to the direction of the wave. Wavelength may be represented as the distance between the two nearest molecules that didn’t vibrate, the two nearest molecules at maximum compression, or the two nearest molecules at maximum rarefaction.
2. f = 1⁄T
f = 1⁄0.03
f = 33. 3 Hz
3. The first wave has a frequency of 33.3 Hz:
f1 = 1⁄T1
f1 = 1⁄0.03
f1 = 33. 3 Hz
The second wave has a frequency of 4 Hz. f2 = 1⁄T2
f2 = 1⁄1⁄4
f2 = 1 ÷ 1⁄4
f2 = 1 × 4⁄1
f2 = 1⁄1 × 4⁄1
f2 = 4 Hz
Therefore, the first wave has a higher frequency.
4. v = I⁄T
v= 4.5⁄0.007
v = 642.9 m/s
5. Wavelength
Crest
Trough
Amplitude