find the upward force in Newton when each of these is under water(density of 1g/cm3) a lump of iron of volume 2000cm3​

Upthrust = 19.6 N

Explanation:

When an object is immersed under water, the upward force it experience is called an upthrust. An upthrust is a force which is applied on any object in a fluid which acts in an opposite direction to the direction of the weight of the object.

Upthrust = density of liquid x gravitational force x volume of object

i.e U = ρ x g x vol

Given: ρ = 1g/ (1000 kg/), volume = 2000 c (0.002 ) and g = 9.8 m/

So that;

U = 1000 x 9.8 x 0.002 (kg/ x x m/)

   = 19.6 Kg m/

U = 19.6 Newtons

The upthrust on the iron is 19.6 N.