Question

Find work done in lifting a body of mass 40 kg and specific gravity 6 to a height 10 m in water

Answer 1

Answer:

2400 J

Explanation:

Work Done = Force × Distance

                   = ( mass * gravitational acceleration ) × d

                   = ( 40 kg * 6 m/s^2 ) × 10 m

                   = ( 240 N ) × 10 m

                   = 2400 Nm  OR  = 2400 J

Note : 1 Nm = 1 J ( joule )

Answer 2

According to my textbook,

Mass= 40 kg

g = 10m/s^2

Specific gravity = 6

Displacement = 10

Work done = (mg-m(sp gr))*dispacement

= (400-240)*10

= (160)*10

1600 J