A somoneter wire resonates with a given tuning fork forming standing waves with five antindoes between the two bridges when a mass of 9 kg is suspended from the wire. Resonates with the same tuning fork forming three antindoes for the same postions of the bridges. the value of M is

Options

A. 25
B. 20
C. 15
D. 10

Answer

A

Explanation

`f=(sqrt((9g)/(mu)))/((2l)/(5))`
`f=(sqrt((Mg)/(mu)))/((2l)/(3))rArr f=(sqrt((9g)/(mu)))/((2l)/(5))=(sqrt((Mg)/(mu)))/((2l)/(3))rArr sqrt(M)=5`.