MHTCET 2016 Physics Solved Paper

(a) For a rolling disc or ring kinetic energy is given by KE =

1

2

mv2+

1

2

lω2
The ring and disc will have same translational kinetic energy, i.e.

1

2

mv2
Rotational kinetic energy of the disc =

1

4

mR2ω2
Rotational kinetic energyof ring =

1

2

mR2ω2
As for ring, 4 J =

1

2

mv2+

1

2

mR2ω2 (∵ I=mR2)
For disc,

1

2

mR2ω2 +

1

4

mR2ω2 = (

4

2

+

4

4

)J = 3J