The Physics of Pressure Washers

A popular brand of pressure washer claims to deliver 330 litres per hour of water at a pressure of 80 bar, drawing 1,400 W of electrical power in the process. Pressure washers of this type are made up of an electric motor that drives a small compressor to pressurize water fed into it through a garde...

Fluid Mechanics: Airplane Wing Design

One of the most important applications of fluid dynamics is in the design of airplane wings. In this SLP, we'll introduce some basic terminology and take a quick look at the relationship between angle of attack, airspeed, and lift. Go to the NASA GRC (2010) link on the Background page, which is...

Fluid Mechanics: Static and Dynamic Pressures

1. A laboratory receives a sample of a metallic alloy composed of aluminum and magnesium. The sample is a solid cylinder with a diameter of 2 cm and a length of 5 cm. Its mass is 15.70 g. What is its density? What is its specific gravity? 2. A boat has a dry weight of 3500 lbs. How many liters ...

Fluid Dynamics Pressure Studies: Pressurized Tank Underwater

Please refer to two attachments for full details including diagram. Phase 1 Valve A, B, and E are closed. Tank A and B are separated and each sealed from the atmosphere. Tank A initially has 3' of air @ 40 psi Tank C and Tank B initially contain air @ 32.476 psi Pipe K is 12" id; ini...

Better Formula for Fluid Mechanics Problem

An open channel having a rectangular cross section is laid so that the rate of grade is 0.00048. The width of the channel is 10.00 ft, and the value of n in Kutter's formula may be taken as 0.011. When the depth of the water in the channel is 4.00 ft, the velocity computed by the Chezy formula is?

Condition for Irrotationality of a 2-d Ideal Fluid Flow

See the attached file. Working from first principles show that the condition for irrotationality of a two-dimensional ideal fluid flow is given by: delta(u)/delta(y) = delta(v)/delta(x) Hence, define in mathematical terms the velocity potential psi, and show that potential lines of consta...

Magnitude and Direction of Shearing Stress

A layer of water flows down an inclined fixed surface with the velocity profile shown in the figure. Determine the magnitude and direction of the shearing stress that the water exerts on the fixed surface for U = 3 m/s and h = 0.1 m. Please refer to the attached figure for a visual representation...

Fluid Mechanics, Moment of Inertia

A symmetrical trapezoidal plate has the following dimensions: the widths of the parallel sides are, respectively, 2.50 ft and 4.50 ft; the perpendicular distance between those sides is 1.50 ft. the plate is submerged in a liquid in a vertical position with the parallel sides horizontal and the short...

Schwarzschild Radius

Suppose two black holes meet and coalesce into one larger black hole. If they have the same mass M and Schwarzschild radius R, a) Express the new single black hole's Schwarzschild radius as a multiple of R. b) Express the average density of the new single black hole in terms of the average d...

Blood flow in an artery

The blood speed in a normal segment of a horizontal artery is 0.106 m/s. An abnormal segment of the artery is narrowed down by an arteriosclerotic plaque to 1/5 of its normal cross-sectional area. What is the difference in blood pressure between the normal and constricted segments of the artery?

A technician is using a laser which is classed '3B'

6. A technician is using a laser which is classed '3B (Restricted)' within the guidelines of Australian Standard AS2211.1-1997 a) What is the maximum radiant exposure the technician could receive in the 0.20s it takes to blink? b) If the MPE for the technician is 6mJm-2, what optical density wo...

Fluid Dynamics and Drag Forces

We would like to know the nature of the drag forces experienced by a sphere as it passes through a fluid. The sphere has a low speed. Therefore, the drag force is highly dependent on the viscosity of the fluid. The fluid density is to be neglected. a) Use dimensional analysis to develop a model f...

Mechanical and Materials Engineering - Fluid Mechanics

Attached is a diagram of an oil storage drum that is open to the atmosphere at the top. Some water was accidentally pumped into the tank and settled to the bottom as shown in the picture. Find the depth of the water h2 if the pressure gage at the bottom reads 158kPa(gage). The total depth hT= 18....

Find the viscosity of the oil.

In a falling-ball viscometer, a steel ball 1.6mm in diameter is allowed to fall freely in a heavy fuel oil having a specific gravity of 0.94. Steel weighs 77kN/m^3. If the ball is observed to fall 250mm in 10.4s, find the viscosity of the oil.

Apparent Weight and Actual Weight

Please help with the given problem: ** Please see the attached file for the figure depicting the described problem ** You must compute the ratio of the actual weight of the crown (W_actual) and the apparent weight of the crown when it is submerged in water (W_apparent). See whether you can follo...

Mechanical Engineering Design

1 The carbon dioxide in a nuclear reactor is maintained at 40 bar (gauge) and 70 deg C. Estimate its density, specific weight and relative density. 2 A water-filled manometer indicates a pressure differential of 2100 N/m2. What is the difference in elevation of the vertical l...

Density and Radius of a Fuel Line

Fuel line in car fuel is going at a certain rate a fuel has certain density and certain radius for the fuel line. Find the speed at which the fuel is moving through fuel line given fuel transfer rate, density of fluid, and radius of fuel line.

Enthalpy calculation

Rotary air compressor problem 1a/ a rotary air compressor increases the absolute pressure of the air from 100 kNm-2 to 230 kNmm-2 and the specific volume of the air is reduced from 0.7m3 kg-1 to 0.46 m3 kg-1. If the internal energy of the air is increased by 40 kj kg-1 find the change in enthalp...

Oscillator response function

Obtain the response of a linear oscillator to a step function and to an impulse function (in the limit t goes to infinity) for over-damped oscillator. Sketch the response functions.

Proposal for airline mechanics

Library Assignment Many staff in the airline service end feel they are overtaxed while others seem to have little to do. Divide up key airline staffing roles among your small group, choosing one role per person, I chose the mechanics. (Preventive Maintenance) Individual Portion The individ...

A deformed hollow cylinder.

Please see the attachment. Assume the volume of the first cylinder is the same as the second after deformation. Can you find a relationship for the volume. The cylinder was uninformed radially.

Problems on Fluid Dynamics

Two problems on fluid dynamics: Problem 1: Water flowing in a pipe with two sections with different cross section areas. To determine pressure, velocity and flow rates in the two sections. Problem 2: Water in a tank being siphoned off. To determine velocity, pressure, flow rate etc.. See t...