- #1

Acidvoodoo

- 10

- 0

hello i have got to these questions in my homework and have no idea how to start them, if anyone can point me in the correct direction i will be greatfull. these questions are to do with a guitar.

the fundemental standing wave pattern shown produces a note of frequency 280hz

is a rough picture down the page i think

1)by placing a finger lightly at certain places on the string it is possible to produce standing waves with other specific frequences

a)sketch one of these standing wave patterns

b)state the frequency of the pattern you have drawn

for this i thought i could just sketch a graph thing with like 2 anti nodes and one nodes to represent if i places my finger in the middle, and then that'd make the frequency double to 560hz, i think. but i'm not too sure at all

2) the speed, v, of a transverse wave along a strectched string is given by

v= √(T/μ)

where T is the tension and μ is the mass per unit length of the string. show that the fundamental frequency is given by

f=1/2L√(T/μ)

where L is the vibrating length of the string between the nut and bridge

i'm not sure what it means to do, am i supposed to sub in the value i got in question one or something like that? grrr i've read the book but it doesn't give worked examples [which is how i usually learne things]

3)assuming both L and μ remmain constant, calculate the new fundamental mode of vibration if the tension were halfed

4)in practice μ , the mass per unit length, changes because the string contracts when the tension is reduced

if the tension is halved, explain whether the mass per unit length will increase or decrease.

i think if the tension halfs, the MPUL will increase

this is really really hard alot of people in the class probably did not understand because the teacher hasn't really covered this yet, but i guess if i know what some of these questions mean i can have a go in the morning, thanks for any starters guys

the fundemental standing wave pattern shown produces a note of frequency 280hz

is a rough picture down the page i think

1)by placing a finger lightly at certain places on the string it is possible to produce standing waves with other specific frequences

a)sketch one of these standing wave patterns

b)state the frequency of the pattern you have drawn

for this i thought i could just sketch a graph thing with like 2 anti nodes and one nodes to represent if i places my finger in the middle, and then that'd make the frequency double to 560hz, i think. but i'm not too sure at all

2) the speed, v, of a transverse wave along a strectched string is given by

v= √(T/μ)

where T is the tension and μ is the mass per unit length of the string. show that the fundamental frequency is given by

f=1/2L√(T/μ)

where L is the vibrating length of the string between the nut and bridge

i'm not sure what it means to do, am i supposed to sub in the value i got in question one or something like that? grrr i've read the book but it doesn't give worked examples [which is how i usually learne things]

3)assuming both L and μ remmain constant, calculate the new fundamental mode of vibration if the tension were halfed

4)in practice μ , the mass per unit length, changes because the string contracts when the tension is reduced

if the tension is halved, explain whether the mass per unit length will increase or decrease.

i think if the tension halfs, the MPUL will increase

this is really really hard alot of people in the class probably did not understand because the teacher hasn't really covered this yet, but i guess if i know what some of these questions mean i can have a go in the morning, thanks for any starters guys

Last edited: