A body of mass 1 kg is attached to one end of a wire and rotated in a horizontal circle of diameter 40cm with constant speed of `2m/s` What is the area of cross section of the wire if the stress developed in the wire is `5 xx 10^6 N/m^2` .

Explanation

`F = T = (mv^2)/r = (1 xx 4)/(0.2)= 20N`
`stress = F//A therefore A = F/(stress) = 20/(5 xx 10^6)`
`4 xx 10^(-6) m^2 = 4mm^2`