Advertisements
Advertisements
Question
Two vessels have the same base area but different shapes. The first vessel takes twice the volume of water that the second vessel requires to fill up to a particular common height. Is the force exerted by the water on the base of the vessel the same in the two cases? If so, why do the vessels filled with water to that same height give different readings on a weighing scale?
Advertisements
Solution 1
Yes
Two vessels having the same base area have identical force and equal pressure acting on their common base area. Since the shapes of the two vessels are different, the force exerted on the sides of the vessels has non-zero vertical components. When these vertical components are added, the total force on one vessel comes out to be greater than that on the other vessel. Hence, when these vessels are filled with water to the same height, they give different readings on a weighing scale.
Solution 2
Pressure (and therefore force) on the two equal base areas are identical. But force is exerted by water on the sides of the vessels also, which has a non-zero vertical component when sides of the vessel are not perfectly normal to the base. This net vertical component of force by water on the sides of the vessel is greater for the first vessel than the second. Hence, the vessels weigh different even when the force on the base is the same in the two cases.
APPEARS IN
RELATED QUESTIONS
Explain why The blood pressure in humans is greater at the feet than at the brain
For a given thrust, pressure is more on a surface of large j area.
A man exerts same pressure on the ground whether he is standing or he is lying.
The unit of thrust is
A body weighing 5 kgf, placed on a surface of area 0.1 m2, exerts a thrust on the surface equal to
How is the thrust related to pressure?
A gum bottle rests on its base. If it is placed upside down, how does the thrust change?
Find the thrust required to exert a pressure of 50000 pascals on an area of 0.05 m2 ?
If someone presses a pointed needle against your skin, you are hurt. But if someone presses a rod against your skin with the same force, you easily tolerate. Explain.
An empty plastic bottle closed with an airtight stopper is pushed down into a bucket filled with water. As the bottle is pushed down, there is an increasing force on the bottom. This is because

A water tank has four taps fixed at points A, B, C, D as shown in the following figure. The water will flow out at the same pressure from taps at
At higher altitudes, atmospheric pressure is ______.
Pressure is directly proportional to the area of contact.
Give reasons why:
heavy trucks are fitted with 6 to 8 wheels
It is easy to compress a gas whereas liquids are ______.
Upthrust = weight of the fluid displaced – apparent weight of the object.
Assertion (A): A sleeping mattress is so designed that when you lie on it, a large area of your body comes in its contact.
Reason (R): This reduces the pressure on the body and sleeping becomes comfortable.
Assertion (A): Wide wooden sleepers are kept below railway lines to reduce pressure on the railway tracks and prevent them from sinking into the ground.
Reason (R): Pressure is directly proportional to the area in which it is acting.
Iceberg floats in water with part of it submerged. What is the fraction of the volume of iceberg submerged if the density of ice is ρi = 0.917 g cm–3?
A vessel filled with water is kept on a weighing pan and the scale adjusted to zero. A block of mass M and density ρ is suspended by a massless spring of spring constant k. This block is submerged inside into the water in the vessel. What is the reading of the scale?
