A syringe is filled with water up to volume `20cm^(3)`. The area of cross-section of the cylinder is`5cm^(2)`. The syringe is held vertically and its `90gm` piston is pushed upward by external agent with constant speed. A water beam coming out of the small nozzle (hole area `1mm^(2)`). Neglecting friction and viscous nature of water, find the work done by the agent [in `10^(-2)`] in fully emptying the syringe. (take `g=10 m//s^(2)`)

Answer

8

Explanation

Height of water column `=20/5=4cm`
Mass of water `=20gm`
By work energy theorem
`W_("ext")=/_\U_("piston")+/_\U_("water")+KE_("water")=8xx10^(-2)`Joule