A uniform solid brass sphere is rotating with angular speed ω0 about a diameter. If its temperature is now in­creased by 100°C, what will be its new angular speed. (Given αB = 2.0 × 10-5 per °C)

Due to increase in temperature, radius of the sphere changes.            Let R0and R100 be radius of sphere at 0°C and 100°C, respectively.R100= R0(1 +α× 100)Squaring both the sides and neglecting higher terms⇒R1002=R02(1+2α×100)By the law of conservation of angular momentum⇒25MR02ω1=25MR1002ω2,R02ω1=R02(1+2×2×10−5×100)ω2ω2=ω1(1+4×10−3)=ω01.004=0.996ω0