A copper wire of negligible mass, length (l), cross-sectional area (A) is kept on a smooth horizontal table with one end fired, a ball of mass 'm' is attached at other end. The wire and the ball are rotated with angular velocity 'omega'. If wire elongates by Delta lthen find Young's modulus of wire. If on increasing the angular velocity from omegato omega^1 the wire breakdown, obtain breaking stress (Delta l lt lt l)

A copper wire of negligible mass, length (l), cross-sectional area (A)

1.	A copper wire of negligible mass, length (l), cross-sectional area (A) is kept on a smooth horizontal table with one end fired, a ball of mass 'm' is attached at other end. The wire and the ball are rotated with angular velocity 'omega'. If wire elongates by Delta lthen find Young's modulus of wire. If on increasing the angular velocity from omegato omega^1 the wire breakdown, obtain breaking stress (Delta l lt lt l)
Answer» Solution :a)`R = L + Delta l` ` F = T mr w^2 = m (l+Delta l)omega^2 ` as `Delta l` in small ` F = ml omega^2 "" y = (Fl)/(Ae)"" y = ((ml omega^2)l)/(A Delta l)` B) we know breaking stress= breaking force/area of cross SECTION ` = (ml omega^(1^2) )/(A)`