MHTCET 2016 Physics Solved Paper

(a) M.O.I. of disc I=

MR2

2

When the disc is melted into solid sphere, then volume remains same.
∴ Volume of disc = Volume of solid sphere
πR2×

R

6

=

4

3

πir3
⇒ r3=

R3

8

⇒ r=

R

2

M.O.I. of solid sphere

2

5

mr2
=

2

5

×m×

R2

4

=

mR2

10

=

I

5

[I = moment of inertia of disc =

MR2

2

]