Question

Three objects, A : (a solid sphere), B : (a thin circular disk) and C : (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed ω about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation

Answer 1

Plate will cool the fastest

Answer 2

Answer:

WC>WB>WA

Explanation:

Number of objects = 3 (Given)

Object a = A solid sphere (Given)

Object b = A thin circular disk (Given)

Object c = A circular ring (Given)

Work done required to bring the objects at rest -

w = loss in KE  = 1/2Iω²  Thus,

ΔW=ΔKE  

ΔW=1/2Iω²

ΔW∝I for same ω, hence-

WA:WB:WC=2/5MR² : 1/2MR²: MR²  

= 2/5 : 1/2 : 1  

= 4:5:10  

= WC>WB>WA

Thus, The amounts of work (W) required to bring them to rest, would satisfy the relation WC>WB>WA.