in an elastic string whose natural length is equal to that of a uniform rod be attached to the rod at both ends n suspende at middle point
a)the rod ll sink until total wrk is non zero
b)the rod ll sink until d total wrk done is zero
c)sinking of rod i nnot determined on yhe basis of work
d)rod ll never sink
i m unale to understand d q :(
1by work-energy theorem,
energy lost for extension + K.E. gained wen the rod sinks = energy gained due to lose in height
but i think the ans is 'c'...
coz...
the rod will sink until the downward force mg is not balanced the upward restoring spring force....
9no sky ans cant be c
rod continues to go down even after balancing forces as it gains some velocity
so it continues going down till velocity =0 ie WD =0
hence ans b
also rod goes up again ( like a vibration )
