Question

A rope having 6 meter length is hanging from a table. The weight per kg of rope is 0.5 kg/meter. Find the work required to lift the rope ?

Answer 1

work = force × displacement
work=mass×acceleration×displacement
=0.5×9.8×6
= 29.4 joules

Answer 2

Given :

The length of the rope hanging = l = 6 meters

The weight per kg of the rope = 0.5 kg/m

To Find :

The work required to lift the rope

Solution :

Let The work done to lift the rope = w  joule

∵  Work done = Force × displacement             .........1

And

Force = mass × acceleration

         = weight per kg

        = 0.5 kg/m

Now, From eq 1

i.e   w = 0.5 kg/m × l

          = 0.5 kg/m × 10 × 6 meters                 ( ∵ g = 10 m/s² )

          = 30  joule

∴  work = 30 joule

Hence, The work required to lift the rope is 30 Joule   Answer