A coin on a rotating table just slips at a distance 1 cm from the centre. If the angular velocity is halved, at what distance will it just slip?
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A coin on a rotating table just slips at a distance 1 cm from the centre. If the angular velocity is halved, at what distance will it just slip?

G1 Physics · Accepted Answer

At limiting friction, μmg = mω²r. Thus ω²r is constant. ω₁²r₁ = ω₂²r₂, with ω₂ = ω₁/2 and r₁ = 1 cm. r₂ = (ω₁/ω₂)²r₁ = 4×1 = 4 cm.