An LPG cylinder [consider it to be perfectly cylindrical] of mass 15 kg containing 10 kg of LPG is performing pure rolling on horizontal surface at speed of 0.5 m/s. Kinetic energy (in J) of cylinder with gas is (Ignore the internal energy of the gas)
The cylinder perform translational as well as rotational motion, whereas the LPG can only perform translational motion as gas cannot be a rigid body.
Therefore the total kinetic energy of the system can be given by,
KETotal=12Icyw2+12mcyv2+12mgasv2
KETotal=12Icyv2R2+12mcyv2+12mgasv2
KETotal=12mcyR2cyv2R2cy+12mcyv2+12mgasv2
KETotal=mcyv2+12mgasv2
KE=15×(12)2+12(10)(12)2=5J