Question

the radius of the neck and the bottom of a soft drink bottle is 1cm and 3cm respectively if a force of 5kgf is applied on the neck of the bottle what is the force at the bottom? pls write the answer with explanation

Answer 1

Answer:

By Pascal's law, the pressure applied to a static and ideal fluid at any point is transmitted equally and undiminished in all directions. In this case the pressure due to the force applied at the neck is transmitted to the bottom.

Thus, pressure at the bottom = pressure at the neck

Therefore, force at the bottom = pressure at the bottom times area of the bottom surface = pressure at the neck times area of the bottom surface.

Fbottom=Pbottom×Abottom=Pneck×Aneck=AneckFneck×Abottom

Since, radius of bottom surface is 5 times the radius of the neck that implies area of the bottom surface must be 25 times that of the neck.

Therefore, force applied at the bottom is 25 times the force applied at the neck. 

⇒FBottom=25×12=300N