A disc is undergoing pure rolling motion on a flat surface. The radius of the disc is 5cm & velocity of centre of mass is 10m/s. What is the ratio of kinetic energy as seen from the ground frame to a frame moving along the disc with a speed of 10m/s?

• A. 1:1, kinetic energy is frame independant
• B. 3:1
• C. 2:1
• D. 1:3