Question

9 A small bird is jumping up and down on an electrical transmission wire at the indicated below, setting up a transverse standing wave that is the fourth harmonic for the stretched wire. (The bird is obviously not drawn to scale. Assume that his mass is small com- pared to the mass of the wire.) 25 m 100 m a) Is t justify your answer. b) Find the wavelength for this standing wave. c) If the bird is hopping with a period of T= 0.5 s, find the speed of traveling waves on this wire. d) If 100 m of wire has a mass of 60 kg, what is the tension F in the wire? he bird hopping at a node or an antinode? Draw a picture of this standing wave to

I need help showing the work for part C and D. The answers are below

'C' = 100 m/s
'D' = 6000 N

Answer 1

C. SEE since its 4th harmonic two wavelengths are present in 100 m

That Means λ = 50 m

now as we know frequency * λ = speed

frequency is 1/time or in this case it will be 2 HZ

speed = 2 * λ =2 * 50 = 100 m/s

D. Here Mass per unit length will be 0.6 kg/m

velocity is 100

v=  √ T/mass per unit length where T is tension

T = v²  * mass per unit length

or T = 100 * 100 * 0.6 =6000N

I HOPE YOU UNDERSTOOD