A solid disc and aring,both ofradius ID cm are placed on ahorizontal table simultaneously, with initial angular speed equal to 10 p rad s_!. Which of the two will start to roll earlier? The co-efficient ofkinetic frictionis is mu_k=0.2

A brass wire 1.8 m long at 27^@C is held taut with little tension between two rigid supports. If the wire is cooled to a temperature of 39 ^@C , what is the tension developed in the wire, if its. diameter is 2.0 mm? Co-efficient of linear expansion of brass = 2.0 XX 10^-5 K^-1 Young’s modulus of brass = 0.91xx10^11 P