Avery powerful vacuum cleaner which has a hose of circular cross section can lift a brick of mass 12 kg when the hose is placed perpendicularly on a horizontal flat smooth face of a brick. what is the minimum radius the hose opening should have to achieve this?

a). 1.9 cm
b). 2.6
c). 1.4 cm
d). 3.2 cm

A). 1.9 cm

Explanation:

m = Mass of brick = 12 kg

g = Acceleration due to gravity = 9.81 m/s²

r = Radius of hose

A = Area =

F = Force =

Let us assume that the pressure required to lift the brick would be atmospheric pressure

The radius of the hose should be 1.9 cm

like poles repel so keep pushing north to north and repels funny to see this