Question

A uniform rope of their mass density `lamda` and length `l` is coiled on smooth horizontal surface. One end is pulled up by an external agent wit consant vertical velocity `v`. Choose the correct option(s)

A. Power developed by external agent as a function of `x` is `P=lamdaxgv`
B. Power developed by external agent as a function of `x` is `P=(lamdav^(2)+lamdaxg)v`
C. Energy lost during the complete lift of the rope is zero
D. Energy lost during the complete lift of the rope is `(lamdalv^(2))/2`

Answer 1

Correct Answer - B::D
`F` applied by external agent `=` Weight `+` thrust force `=lamdaxg+lamdav^(2)`
Energy lost in the complete lift `=W_(F)-DeltaK.E. -DeltaU=(lamda lv^(2))/2`