More about stationary waves on strings

Question 1

What is the first harmonic pattern of vibration?

Answer 1

seen at the lowest possible frequency that gives a pattern antinode at the middle node at either end

Question 2

What is the second and third harmonic?

Answer 2

second: node at middle and at either end third: nodes are a distance of 1/3 from either end and an antinode at the middle

Question 3

What are the equations for the first three harmonics

Answer 3

λ₁ = 2L

f₁ = c / λ₁

f₂ = c / λ₂ = C / L = 2F₁

f₃ = c / λ₃ = 3c / 2L = 3F₁

Question 4

What happens to the crest as it reflect at the fixed end?

Answer 4

travels back along the string in reverse phase

crest reverse

Question 5

What is the equation for the time taken for a wave to travel along the string and back?

Answer 5

t = 2L / c

Question 6

What is the equation for the time taken for the vibrator (wave source) to pass through a whole number of cycles?

Answer 6

m / f

f = frequency

m = whole number

therefore

2L / c = m / f

Question 7

What affect on pitch does raising the tension in the string?

Answer 7

shortening the length

increases freq

increasing pitch

Question 8

What causes the node?>

Answer 8

destructive interference

in anti-phase

Question 9

WHat causes the anti-node?

Answer 9

constructive interference

reinforcement

Question 10

How is energy transferred in a staitonary wave?

Answer 10

it isn’t