Question

4. A ring and a disc roll on the horizontal surface without slipping with same linear velocity. If both
have same mass and total kinetic energy of the ring is 4 J then total kinetic energy of the disc is
A) 3J
B) 4J
C) 5 J
D) 6J​

Answer 1

We know that,
Mass of ring = mass of disc ........ i
Linear velocity of ring= linear velocity of disc .........ii
Also,
1/2 * Mass of ring * (Linear velocity of ring)^2 = 4J (Given)
1/2 * Mass of disc * (Linear velocity of disc)^2 = 4J (From i and ii)
Therefore total kinetic energy of the disc is B) 4J