Question

Air from a metal can is removed so the pressure in the can decreases to 70000Pa, the can is then sealed. The pressure from outside the can is atmospheric pressure which is 100kPa. The area of one side of the can is 1.5m2, find the resultant force on this side of the can.

Answer 1

F = 45 KN = 45000 N

Step-by-step explanation:

Considering the downward direction as the positive direction:

`P = P_1 - P_2`

where,

P = Resultant Pressure = ?

P₁ = Atmospheric Pressure = 100 KPa

P₂ = Pressure inside the can = 70000 Pa = 70 KPa

Therefore,

`P = 100\ KPa - 70\ KPa\\P = 30\ KPa`

Now the resultant force will be given as:

`F = PA`

where,

F = resultant force = ?

A = Area of side of can = 1.5 m²

Therefore,

`F = (30\ KPa)(1.5\ m^2)\\`

F = 45 KN