Calculating Thrust on Curved Surface of Cylindrical Vessel

[Pyrus]

Homework Statement

A large cylindrical vessel contains water to a height of 10 m. It is found that the thrust acting on the curved surface is equal to that at the bottom. If atmospheric pressure can support a water column of 10 m, the radius of the vessel is:-
(a) 10 m (b) 15m (c) 5 m (d) 25 m

Homework Equations

P=F/A
Vol = πr*r*h

The Attempt at a Solution

 

[tommyxu3]

It is found that the thrust acting on the curved surface is equal to that at the bottom.

This may be a key to help you find their relation. Can you get any idea from this information?

 

[haruspex]

Homework Statement

A large cylindrical vessel contains water to a height of 10 m. It is found that the thrust acting on the curved surface is equal to that at the bottom. If atmospheric pressure can support a water column of 10 m, the radius of the vessel is:-
(a) 10 m (b) 15m (c) 5 m (d) 25 m

Homework Equations

P=F/A
Vol = πr*r*h

The Attempt at a Solution

Since you have posted no attempt, I assume you are stuck on interpreting the question.

It certainly is strange. I assume this is an upright cylinder. By "thrust acting on the curved surface" they should mean the force acting on the cylinder walls. Since force is a vector, by symmetry, the net force is zero.
So what do you think they might mean?

 

[Pyrus]

I stuck up in force acting on curved surface of cylinder.

 

[haruspex]

I stuck up in force acting on curved surface of cylinder.

In understanding what they mean or in calculating it?