Course:PHYS341/Archive/2016wTerm2/Assignments/A7

Practice Questions for Quiz 7, Friday Mar 17

Project draft also due Mar 17 at 17:00

Textbook sections covered: 16.1-10, 17.1-2, 17.6-9

1. The internal structure of violin family instruments is deliberately asymmetric because

(a) the bridge has a more complicated shape than that of a guitar.
(b) the player sometimes needs to play more than one string at a time
(c) of the stick-slip mechanism of the bowed strings.
(d) the bow produces a downward force on the bridge.
(e) the bow produces a sideways force on the bridge. ✓
(f) there are no frets on the fingerboard.

2. The stick-slip mechanism of the bow can excite a string at precisely the right frequency because

(a) the bow only grabs the string when it is moving at the same velocity as the string. ✓
(b) the bow only releases the string when it is moving at the same velocity as the string. [true, in fact it cannot be otherwise, so it is not as good a completion of the sentence as (a)]
(c) the bow motion contains all frequencies.
(d) the bow produces a downward force on the bridge.
(e) the bow produces a sideways force on the bridge.
(f) the tiny ridges on the horse hairs pluck the string.

3. A string on a lute-family instrument feels too slack, even when tuned to the right pitch. Which of the following solutions could work?

(a) tighten the string.
(b) replace the string with one of the same diameter but made of a heavier material. ✓
(c) replace the string with one of the same diameter but made of a lighter material.
(d) replace the string with one made of same material but thinner.
(e) replace the string with one made of same material but thicker. ✓

4. Compare the piano action with that of a harpsichord. Circle any statement that is correct:

(a) A plectrum plucking a string makes a louder sound if moves faster.
(b) A plectrum plucking a string makes the same volume of sound regardless of how fast it moves. ✓
(c) A hammer striking a string makes a louder sound if moves faster. ✓
(d) A hammer striking a string makes the same volume of sound regardless of how fast it moves.