# Vertical pressure on soft drink can

1. Mar 12, 2015

### reshald

1. The problem statement, all variables and given/known data
In a classroom demonstration, the pressure inside a soft drink can is suddenly reduced to essentially zero. Assuming the can to be a cylinder with a height of 13cm and a diameter of 6.5cm , find the net inward force exerted on the vertical sides of the can due to atmospheric pressure.

2. Relevant equations
Pressure= force/area
area of a cylinder is 2πrh +2πr2
force due to gravity is mg

3. The attempt at a solution
I know that because there is no pressure inside the can to counteract the air pushing inward, the can collapses but I am not sure how to calculate the force on the vertical sides of the can. Atmospheric pressure is 1 atm at sea level which is 101325 Nm-2. If the pressure on the top of the can is the same as that of the sides than you multiply the pressure by area to get force which gives 6991425 but this is incorrect probably because the pressure on the top isn't the same as the pressure on the sides but I don't know what the formula for it is.

2. Mar 12, 2015

### Bystander

What's the area of the cylindrical surface of the can?

3. Mar 12, 2015

### reshald

Thank you that fixed it. Also I didn't convert the diameter into meters. Thank you.

4. Mar 12, 2015

### Staff: Mentor

Actually, this is a very poorly worded question. The net force by the air on the vertical sides of the can has to take into account the direction of the forces, and this results in a net force of zero.

Chet