-->

Mechanical Properties Of Fluids

Question
CBSEENPH11019321

A spring oscillates with frequency 30 per minute when loaded by M kg. On increasing the load by 0.5 kg, the frequency of oscillation decreases to 24 per minute. Find M.

Solution

The frequency of oscillation is given by,
                    straight nu space equals space fraction numerator 1 over denominator 2 straight pi end fraction square root of straight k over straight m end root 
Given, when m = M ; straight nu space equals space 30 space per space min
therefore space 30 space equals space fraction numerator 1 over denominator 2 straight pi end fraction square root of straight k over straight m end root space space space space space space space space space space space space space... space left parenthesis 1 right parenthesis thin space

When comma space straight m space equals space straight M space plus space 0.5 comma space then space

space space space space space space space space space space space space space straight nu space equals space 24 space per space min

So comma space space 24 space equals space fraction numerator 1 over denominator 2 straight pi end fraction space square root of fraction numerator straight k over denominator straight M plus 0.5 end fraction end root space space space space space space... space left parenthesis 2 right parenthesis thin space

Dividing space equation space left parenthesis 1 right parenthesis space by space left parenthesis 2 right parenthesis comma space we space get space

space space space space space space 30 over 24 space equals space square root of fraction numerator straight M space plus space 0.5 over denominator straight M end fraction end root space

rightwards double arrow space space fraction numerator straight M space plus space 0.5 over denominator straight M end fraction space equals space 25 over 16

rightwards double arrow space space space 16 space straight M space plus space 8 space equals space 25 space straight M space

rightwards double arrow space space space space 9 space straight M space equals space 8 space

rightwards double arrow space space space space space space straight M space equals space 8 over 9 kg