Answer:
Step-by-step explanation:
mass of the coin m = 4.2 x 10⁻³ kg
radius of circular path r in which coin will move = 15 x 10⁻² m
coefficient of static friction μs = .7
at maximum angular velocity of ω , limiting force of friction will provide centripetal force to coin to rotate in circular path .
so centripetal force = frictional force
mω²r = μs x mg
ω²r = μs x g
ω² = μs x g / r
= .7 x 9.8 / 15 x 10⁻²
= 45.73
ω = 6.76 radian / s.