Formulas And Idea To Kniw

Question 1

What is a standing wave

Answer 1

With the right frequency a traveling wave can reflect back on itself and due to the superposition principle. The wave will appear to stand still

Question 2

The 2nd harmonic is the ____ standing wave

Answer 2

3rd standing wave

Question 3

Resonant frequency

Answer 3

Frequency at which the driving force equals the natural frequency of the system f sub zero. The system will be in resonance

Question 4

When the driving force matches the the natural frequency and there are two pendulums one with length L and the other .3 L. Which has higher admitted if the driving force matches the res freq of the .3L

Answer 4

The .3L pendulum will have largest amplitude because of the

Question 5

What is fundamental frequency in a tube with one end closed and one end opened

Answer 5

^=4L

Question 6

Wave speed of a fixed string

Answer 6

The square root of

Tension force divided
Mass per length

Question 7

How many nose in a 2nd harmonic

Answer 7

3 nodes

Question 8

What is 1st harmonic..how many nodes and anti nodes

Answer 8

It’s a jump rope
It has two nodes

All harmonics are multiple of this number
Has 2 nodes

So fourth harmonic is 4 nodes

Question 9

Speed of sound in a fluid

Answer 9

Root of

Bulk modulus divided
Equilibrium density

Question 10

Wave equation

Answer 10

Wave length times frequency

Question 11

At first harmoinc what is wavelength

Answer 11

2L

Also called fundamental frequency

Question 12

Fundamental frequency equals

Answer 12

Velocity. Divided by 2L

Derived from wave speed equation and the fact that wavelength at f zero is 2L

Question 13

So the pattern of finding any harmonic

Answer 13

N times the fundamental frequency

No remember that the fundamental frequency equaled velocity divided by 2L

And remember that velocity equals root force divided by mass per unit you get

Question 14

What does a wave length in side an open end tube look like..draw it

Answer 14

It goes anti node node and then anti mode

Question 15

Pattern of a pipe closed at one end and the resonant freq

Answer 15

1st
Frq equals velocity/ 4L

For every harmonic after you simply add 1/2 to 1/4

So the next is 3/4 and then 5/4 and then 7/4

Question 16

Resonant freq of open end pipe

Answer 16

Frequency equals velocity/2L

Every frequency after is just multiplying by whatever one you want

And then take into account that v/2L is the fundamental and you get
Maybe nth frequ is just the fundamental multiple n times

Question 17

What is velocity of a wave

Answer 17

Frequency times its wave length