Methink the qn and ans given to problem ( 6 ) are also self- cotradictory !!

 

It is said that the mass of the wheels are negligble .

 

Then how in the total energy expression  of the system can a rotational energy term possibly occur ?

 

On the other hand consider a wheel of mass M be attached to the end of the spring . If u carry out the analysis u will find that  is indeed greater than sqrt( k/m ) .

 

Plz explain it also .