(i)Define thrust and pressure.

(ii)Give the mathematical formula that relates thrust and pressure.

(iii)Define 1 Pa.

(iv)Calculate the pressure exerted by a block of weight 500 N, if the surface area in contact is 2.5 cm

(i) Thrust is the force acting on a body perpendicular to its surface. Thrust acting on unit area is called pressure.

(ii)Mathemtically, pressure = force / area = thrust / area

or

p=F/A

(iii)The pressure exerted by 1 N of force acting perpendicular on the surface of ${{1m}^{2}}$ area is called 1 Pa

1 Pascal = 1 Newton per metre square.

or

1 Pa = ${{1m}^{2}}$

(iv) Here, weight = 500 N

Area = 2.5 ${{cm}^{2}}$ = 2.5 x ${{10}^{-4}}$ ${{m}^{2}}$

Pressure = Weight / Area = 500 / 2.5 x ${{10}^{-4}}$ = 2 x ${{10}^{6}}$ Pa