Question

One end of a horizontal wire is fixed and the other passes over a smooth frictionless pulley and has a heavy body attached to it. The fundamental frequency is 400 Hz. When the body is totally immersed in water, the frequency drops to 350 Hz. Find the density of the body. [ρ_ω = 19/cm³].

Answer 1

Given :

f₁= 400 Hz. f₂ = 350 Hz

[ρ_ω = 19/cm³

We know that, for a string under tension T, the frequency of oscillation

l: length of wire,μ  : mass per unit length

∴ T₁ = mg T₂ = mg – B

Now m: vρ v: volume ρ: mass density

∴ mg = vρg B = vρ_ωg

g = 9.8 m s^-2

Given: