How much force must be applied on a blade of length 4cm and thickness of 0.1mm to exert a pressure of 4000000pa?

F= 403429 kpa

Explanation:

Pressure is the product of force and area

Mathematically,

P=F*A where F is force and A is area.

A= 40 *0.1 = 4mm² convert to m²

A= 4e⁻⁶ m²

P= 4000000 pa

F= P/A = 4000000/4e⁻⁶

F= 403428793.493 pa

F= 403429 kpa

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

because if the tool that you are using is not balanced it there would be false mass.