Question

when a small mass m is suspended at lower end of an elastic wire having upper end fixed with ceiling. there is loss in gravitational potential energy let it let it be X,due to extension of wire,. mark correct option 1) the lost energy can be recovered 2) the lost energy is irrecoverable 3) only X/ 2 amount of energy is recoverable 4) only X/3 amount of energy is recoverable

Answer 1

The correct answer is option (1) The lost energy can be recovered .

Explanation :

• Here in this case the work done on the mass m ( suspended at lower end of the elastic wire whose upper end is fixed with the ceiling) is by gravitational force .

• This work by gravitational force is done against the recovering force ( stress) of the material i.e. due to the elastic property .
• Now since both the forces are conservative , so the net work done on the mass m is recoverable .