Fluids – Hub of related Posts

In this post, you will find a set of Numericals on Floatation for class 9. In the solutions, you may note the formulas that are used to solve these Floatation class 9 Numericals. Floatation Class 9 Numericals (with solution) Question 1] A body experiences an upthrust F1 in river water and F2 in seawater when dipped up to the same ...

Question 1) The density of mercury is 1.36 × 104 kg m–3. Calculate the length that a mercury barometer will have when the atmospheric pressure is 101 kPa. Answer 1) Rearranging the atmospheric pressure equation related to Mercury Barometer gives the expression for the length of mercury: Atmospheric Pressure P = Δhρg=> Δh = P/(ρg) ............................. (equation 1) Given: density ...

Let's see how Mercury Barometer expresses atmospheric pressure in terms of the length or height of the mercury column as a variant of the manometer. Mercury Barometer Mercury Barometer can be regarded as a variant of the manometer, in which the U-tube has been straightened out and one end submerged in mercury (figure 1). This means that the mercury level ...

Use of U-tube manometer The U-tube manometer is used to measure pressure differences between two gases; typically one of these is air at atmospheric pressure. pressure difference formula used The U-tube manometer operates on the principle that P = ρgh. The pressure difference Δp = liquid density ρ × g × height difference between the two arms h. Use and ...

This post is on Numericals on Density & Relative Density for Class 9. Formulas Used  Mass = Volume x density Volume = mass/density Density = mass/volume Relative density RD of a substance = mass of the substance/mass of water of the same volume Relative density RD of a substance = density of the substance/density of water Numericals on density and ...

In this post, we publish a bundle of Questions and answers related to Buoyancy and Buoyant force. Why does a stone sink but a wood float? A stone is denser than water. This means, if you compare the mass of a stone to the mass of the same volume of water, the stone’s mass will be greater. Therefore its weight ...

What is the difference between laminar and turbulent flow? The film of fluid that touches the container does not move because of friction with the container’s surface. But the fluid in the middle of the stream does. In laminar flow the transition from not moving to full-speed motion is continuous. Each thin film of water moves slightly faster than the ...

Hydraulics deals with the use of liquid in motion, usually in a device such as a machine. Oil is the most common liquid used in pumps, lifts, and shock absorbers. Whereas hydraulics uses liquids to achieve mechanical advantage, pneumatics uses compressed gas. Since gases can be compressed and stored under pressure, releasing compressed air can provide large forces and torque ...

Here, we will solve a Numerical problem based on Capillary Rise & Capillarity. Numerical assignment (on Capillary Rise & Capillarity) solved 1) A glass tube of radius 0.4 mm is dipped vertically in the water. Find up to what height, the water will rise in the capillary. If the tube is inclined at an angle of 60° with the vertical, ...

In this post, we have discussed capillarity and Capillary Rise. We also did the derivation of the formula of the height for Capillary Rise. We have added one assignment at the end of this post, that you must try (also check the solution - the link is provided) Capillarity If a capillary tube of glass is dipped in liquid like ...

This post presents a list of facts and formulas from the Fluid flow chapter of class 11 (grade 11) physics. Formulas from the Fluid Flow chapter of class 11 1 ) Pressure is the force per unit area exerted by a fluid on its surroundings: P = F/A Its SI units are pascals where 1 pascal = 1 newton/meter squared ...

Cohesion refers to the attraction of molecules for other molecules of the same kind, but Adhesion is the attraction of molecules of one kind for molecules of a different kind. In this post, we will learn in detail what exactly Cohesion and Adhesion are, and this will help to understand the difference between them. To discuss these we will consider the cohesion ...

A liter of water has a mass of 1.00 kg, but the same volume of methylated spirits has a mass of only 0.79 kg. We can say that the density of methylated spirits is 0.79 that of water. This is called its relative density (RD) or its specific gravity (SG). The two terms ( relative density and specific gravity ) ...

The viscosities of liquids can be compared by observing their rates of flow through a glass tube. A simple device called a Redwood viscometer can be adapted easily for the laboratory. Comparing viscosities using a viscometer A viscometer is shown in Figure 1. Using the apparatus in Figure 1, fill the funnel with liquid to a level just above the ...

In this post, we are presenting a few sets of MCQ worksheets with questions on Excess pressure & Angle of contact (both from the Surface Tension chapter of Physics). You can also try our MCQ worksheet on Surface tension concepts and surface energy. Excess pressure - MCQ worksheets 25) Two bubbles A and B (A > B) are joined through ...

In this post, we are presenting a few sets of MCQ worksheets with questions from the Surface Tension chapter of Physics. These sets include questions on Cohesive force and adhesive force, surface tension, and surface energy. And here is the link to the next part of this surface tension MCQ set. MCQ on excess pressure & angle of contact. Problems ...

An object in a fluid will sink if the object’s weight is greater than the buoyant force (the weight of the fluid that the object displaces). An object floats only when the buoyant force on the object is equal to the object’s weight. An object is buoyed up until the part of the object underwater displaces an amount of water ...

In this post, we will quickly revise Archimedes' Principle and its legendary background. Then we will solve a few numerical problems in physics using this principle. Archimedes’ Principle and Buoyancy If an object is submerged in a liquid, the object displaces a volume of the liquid equal to the volume of the submerged object. There is a Legend that Archimedes ...

In this post, we will derive the equations for the Excess pressure inside Liquid Drop and Liquid Bubble. Small-sized liquid drops and a bubble are spherical in shape due to surface tension. The liquid surface is curved; therefore there is an excess pressure; p; inside the liquid drop or a bubble. Liquid Drop - Excess pressure equation derivation Consider a ...

In this post, we will cover an important topic of the Surface Tension chapter. And this topic is Excess Pressure Across a Curved Liquid Surface. What is excess pressure across the liquid surface In general, a liquid surface may be a plane, concave or convex. Due to the shape of the liquid surface and the force of surface tension, in ...

In this post, we will discuss the concepts of the Angle of Contact which is related to surface tension. Let's define and understand it first. Define the Angle of Contact How much curved a meniscus will be, is expressed in terms of angle of contact. The angle of contact, θ; between a liquid and a solid is the angle enclosed ...

In this post, we will solve a few selected numerical problems from the Surface Tension chapter (Physics class 11). Numerical problems from the Surface Tension chapter 1 ) A wire bent in the form of a ring of radius 5 cm rests on the surface of the water in a beaker. A force of 4.4 gwt is required to pull ...

Surface tension (S) equals the free energy (E) of the liquid surface (Temperature remaining constant). Let's see how we can prove that mathematically using an experimental setup. how to prove that Surface tension equals the free energy of the liquid surface? figure 1: setup to prove that the Surface tension (S) equals the free energy (E) of the liquid surface ...

The surface of a liquid at rest behaves like a stretched membrane. It tries to contract and have a minimum surface area. This property of the liquid surface is known as surface tension. Illustrations of Surface Tension | examples of surface tension Small liquid drops are always spherical in shape. It can be shown that for a given volume; the ...

Here in this post, we will convert L atm to Joule. L atm is also known as Litre Atmosphere. L atm to Joule L atm is the product of 2 units and these 2 units are Litre (unit of volume) and Atmospheric pressure (or atmosphere which is a unit of pressure). L atm, hence, is the product of volume and ...

In this post, we will solve a numerical problem based on the principle of a car hydraulic braking system. To solve this numerical, we will take the help of the concepts of the lever, and the pressure principle of Pascal. We will go through the problem statement first and then solve the numerical step-by-step. Numerical on hydraulic braking principle - ...

In this post, we will see how to solve numerical problems on terminal velocity. We will discuss the concept in brief and then take sample problem/s and solve them using the appropriate formula of terminal velocity. Theory & formula to solve terminal velocity numerical The first numerical problem in this post is about a spherical ball that falls through a ...

Here we will derive the formula of viscosity using Stoke's law. We have already derived one expression of viscosity using the flow of a viscous fluid between two parallel plates. Now we derive a different equation of viscosity or coefficient of viscosity in terms of terminal velocity. When a sphere is released and allowed to fall freely in a fluid, ...

Pascal's Law states that any change in the pressure applied to a completely enclosed fluid is transmitted undiminished to all parts of the fluid and the enclosing walls. Let's see how Pascal's principle is applied to design hydraulic car brakes. When the brake pedal is pushed, the piston in the master cylinder exerts a force on the brake fluid. And ...

This post centers around the Fluid Dynamics Class Notes for class 11 (includes viscosity) for boards like ISC, CBSE, IGCSE, etc. A fluid is a collection of molecules that are randomly arranged and held together by weak cohesive forces and by forces exerted by the walls of a container. Both liquids and gases are fluids. The mechanics of fluids in ...

The Reynolds number, Re is a dimensionless quantity and there is a ‘rule of thumb’ for flow in a pipe using the Reynolds number Re. When Re is less than 1000, flow can be taken to be laminar; when Re is greater than 2000, the flow will be turbulent. Reynolds number of a fluid flow depends on the radius of ...

Bernoulli’s equation describes the relationship between pressure and velocity in fluids quantitatively. Hence, this equation is named after its discoverer, the Swiss scientist Daniel Bernoulli (1700–1782). Bernoulli’s equation states that for an incompressible, frictionless fluid, the following sum is constant: P+(1/2)ρv2+ρgh=constant, where P is the absolute pressure, ρ is the fluid density, v is the velocity of the fluid, h ...

In this post, we will discuss two topics related to fluid dynamics. These topics are Streamlines and the Equation of Continuity with derivation. This physics tutorial is apt for class 11 physics for ISC, CBSE, IGCSE, and other boards (grade 11 and 12 for international boards). Streamlines The path taken by a fluid particle under a steady (laminar) flow is ...

Determination of Density of a Solid by Using a Measuring Cylinder Dividing the mass of a solid by its volume gives its density. The mass of a solid can be determined accurately by using a physical balance. The volume of an irregular-shaped solid can be determined by using a measuring jar (cylinder). To measure the volume of a solid, note ...

As we go to higher altitudes such as top mountains the atmospheric pressure is found to decrease. The following are the reasons behind atmospheric pressure fall at higher altitudes: (i) Density of air decreases at higher altitudes.(ii) Height of the air column above us also decreases. A variation between the altitude and pressure/density is shown in the graph given below ...

Here we will work on the derivation of the Terminal Velocity equation or formula using Stokes' Law. We will consider a situation where a solid sphere moving slowly in a fluid to derive the Terminal Velocity equation. We will also solve a numerical problem using the terminal velocity equation. Derivation of Terminal Velocity Equation using Stokes' law When an object ...

Stokes' Law and its formula: Eminent physicist Sir Stokes investigated fluid dynamics and came up with an equation for the viscous drag (F) on a small sphere at low speeds. This formula is now called Stokes' Law. The Stokes' Law formula is represented in this way: F = 6 πrȠV ............ (1)where r is the radius of the sphere (with ...

In this post, our topic of discussion is the Buoyant Force formula. As we go through it here, we will use this formula to solve a sample numerical as well. Remember that, the upward buoyant force caused by Buoyancy is equal to the weight of the displaced fluid. Buoyant Force Formula Note: Upward buoyant force caused by Buoyancy = the ...

Archimedes' principle states that when a body is immersed partially or completely in a liquid, it experiences an upthrust, which is equal to the weight of the liquid displaced by it. This principle of Archimedes applies equally well to gases also. So the principle can be stated alternately as follows: Archimedes’ Principle states that when a body is wholly or ...

Bernoulli’s principle is named for Daniel Bernoulli, who presented it in 1738, and it concerns the relationship between pressure and flow speed in fluids. In its simplest form, Bernoulli’s principle states that increasing flow speed in fluids corresponds to decreasing pressure, and vice versa. Airplane Wings and Sails are two areas where Bernoulli’s Principle is applied. Let's find the details ...

Here we will define & discuss the concepts of viscosity and derive the formula of the coefficient of viscosity. When we pour a glass of water, it flows freely and quickly. But when we pour honey that flows slowly and sticks to the container. The cause behind this difference is fluid friction, both within the fluid itself and between the ...

In this post, we will study the concepts of Buoyancy. We will start with some common examples to understand the phenomenon, and then define it and its related terms like Buoyant force. We will also explain Buoyancy and Buoyant force and derive related formulas. Buoyancy meaning | What do you mean by Buoyancy We have certainly experienced Buoyancy knowingly or ...

Density is the mass per unit volume. The unit of density in SI is Kg/meter3. The relative density or specific gravity of a substance is the ratio of its own density and the density of water. It’s a number only without any unit. What is the difference between density and relative density? Density is the mass per unit volume. So ...