problem 81 (waves)

look at the slide

the point at the freen end is an antinode

• we consider cases

1. no nodes inbetwee

• the distance between node and antinode is quarter the wavelength (L/4)

1. 1 node

3L/4 (l is lambda)

1. 2

7l/4 (7 quarters) (not , check slide)

1. 3
3. 4

all of these are equal is the fixed length

the fomrula says