A body is hanging from a rigid support. by an inextensible string of length `'1'` . It is struck inelastically by an identical body of mass in with horizontal velocity `v=sqrt(2gl)` the tension in the string increases just after the striking by

Options

A. mg
B. 3 mg
C. 2 mg
D. None of these

Answer

C

Explanation

(c )`mv_(0)=(m+m)v implies v=(v_(0))/(2)` ,brgt `T=(2 mv^(2))/(l)+2 mg =(m(2gl))/(2l)+2 mg[because(2mv^(2))/(l)`=Centrifugal force]
`T=3 mg`
`therefore` Increase in tension =3 mg-mg=2 mg