Flag Wave Motion> A string tied between x = 0 and x = ℓ vib...
question mark

A string tied between x = 0 and x = ℓ vibrates in fundamental mode. The amplitude A, tension T and mass per unit length μ is given. Find the total energy of the string.

Hrishant Goswami , 10 Years ago
Grade 10
anser 1 Answers
Jitender Pal

Last Activity: 10 Years ago

Hello Student,
Please find the answer to your question
Here ℓ = ℷ/2 or ℷ = 2 ℓ Since, k = 2π/ℷ = 2π/ ℓ = π/ ℓ
The amplitude of vibration at a distance x from x = 0 is given by A = a sin k x
Mechanical energy at x of length dx is
dE =1/2 (dm) A2 ω2 = 1/2 (μdx) (a sin k x)2 (2πv)2
= 2π2 μv2 a2 sin2 kx dx
But v = vℷ
∴ v = v/ℷ ⇒ v2 = v2/ℷ2 = T/μ / 4 ℓ2 [∴ v = √T/μ ]
∴ dE = 2π2 μ T/μ / 4ℓ2 a2 sin2 {( π/ℓ )x} dx
∴ Total energy of the string
E = ∫ dE = ∫02 μ T/μ / 4ℓ2 a2 sin2 (π x/ ℓ) dx
= π2 Ta2/4 ℓ

Thanks
Jitender Pal
askIITians Faculty

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...