Explore BrainMass

Mechanical Engineering

Saturated vapor at pressure in rigid tank

A 1.8m^3 rigid tank contains steam at 220C. One third of the volume is in the liquid phase and the rest is in the vapor form. Determine: A) The pressure of the steam B) The quality of the saturated mixture C) the density of the mixture

Oblique Pictoral Sketches

Using the front view and side view of an object sketch the pictorials or 3-D pictures of the objects in the attached file.

Freebody Diagrams Problem

Draw a freebody diagram of a bar AB as well as the forces that are acting upon that bar. Use the attached file.

Finding tangent and cosine

Find the expressions (in terms of a and b) for cosine theta and tangent theta. Use the picture attached. See attached file for full problem description.

Pre-heating of combustion air?

250 psi saturated steam at approximately 400 degrees F is used to pre-heat ambient air at 60 degrees F through a 100% theoretically efficient heat exchanger. The desire is to raise the temperature of the ambient air from 60 degree F to 350 degrees F ---- I need to calculate the amount of steam energy in BTU's per minutes and

Entropy Generation in a Steam Turbine

Steam at a rate of 15lbm/s enters a turbine at 500 Psia, 800f and exits at 5 Psia. For a reversible, adiabatic process (iseentropic), what is the work out of the turbine in Btu/s and what is the entropy generation?

Design Air Mass Flow Required

Water enter a cooling tower at 400C and drops 150C of temperature before exit. The tower receives atmospheric air at 200C and 40% relative humidity. The air leaves the tower at 350C and 95% relative humidity. If the atmospheric pressure is 1.01325 bar determine the design air mass flow required to handle 12,000 litres/min of co

Material properties question

1) Three samples of aluminum are subjected to a constant stress and the times required to produce a constant strain of 0.1% during steady state creep at different temperatures are shown in table 1 below. Temperature (00C) 151 205 258 Time (hours) 100 1.0 0.028 Use this information to determine grap

Refrigerant 134a leaves the evaporator as saturated vapor

Refrigerant 134a leaves the evaporator as saturated vapor at 1.4bar and is heated at constant pressure to 20 degrees C before entering the compressor. After isentropic compression to 12bar, the refrigerant passes through the condensor exiting at at 44 degrees C, 12 bar. The liquid then passes through the heat exchanger, enteri

Cooling/Dehumidification of an air stream

A 1000 m3/minute air stream at atmospheric pressure is at a temperature of 82.2oC and a humidity of 60%. We want to cool the air + water vapor to 8.9oC to condense the water vapor. Determine the sensible cooling and latent cooling required to drop the temperature of the air mass from 82.2oC to 8.9oC and condense the water vapor.

The step response of the system

Problem 1 only. See attached file for full problem description. In the following circuit, v1(t) is the input voltage and v2(t) is the output voltage. Calculate the step response of the system. i.e., calculate the output v2(t) when the input is a unit step function.

Sensible heat, latent heat, and heat of vaporization of water

A 1000 m3/min air flow at 170 degrees F and containing 60% relative humidity needs to be cooled to 48 degrees F to promote condensation of the water vapor in the air. How would you calculate the sensible heat, the latent heat, and determine the latent heat of vaporization of the water vapor in this air stream as the air is co

Dimensional Analysis and Similarity

Consider flow in a pipe of diameter D through a pipe bend of radius Rb. The pressure loss p through the bend is a function of these two length scales, plus density , viscosity  and average flow velocity V. a) Use dimensional analysis to rewrite this function in terms of dimensionless PI groups. b) In analyzing data fo

A piston-cylinder device has a volume of 0.1 cubic meters

A piston-cylinder device has a volume of 0.1 cubic meters and contains 0.5kg of steam at 0.4 MPa. Heat is transferred to the steam until the temperature is 300 degrees Celsius, while the pressure remains constant. Determine the heat transfer for this process in kilojoules. (My professor told us to use steam tables not the i

Determining maximum value of the average normal stress

In the problem attached, why are the pins not included in the calculation of area when the links are in tension? But the pins are included in the calculation of area when the links are in compression. See attached file for full problem description.

Multi degree of Freedom Systems.

A Problem about Multi degree of Freedom Systems. See attached file for full problem description. Consider the triple pendulum in the attache3d, linearize the equations of motion by assuming small angles theta, solve the associated eigenvalue problem for the case in which m1 = m2 = m3 = m, L1 = L2 = L3 = L and plot the natura

Stress and Loads - largest permissible value load

The cross section of the beam AD in Question 1 (attached). 1. Knowing the allowable normal stress due to bending +110 MPa in tension and -150 MPa in compression, find the largest permissible value load W if beam AB is not overstressed. See attached file for full problem description.

Two solid steel shafts are connected by gears

Two solid steel shafts (G = 11.2 x 106 psi) are connected by the gears shown. Ends B and D are fixed. Assume points A and C are where the gears meets the shafts. What is the maximum shear stress in shaft CD under the loading shown? Choose One: 7.832ksi 6.987ksi 6.443ksi 5.844ksi What is the angle through which end C r

Determine the size of the footing

A 20-kips axial load is applied to a short wooden post which is supported by a concrete footing resting on undisturbed soil as shown. Determine the size "b" of the concrete footing if the average bearing stress on the soil is not to exceed 30 psi. a. b = 25.8 in. b. b = 22.4 in. c. b = 18.3 in. d. b = 15.8 in.

Mass-flow rate

Consider a flow for which the velocity vector is: u=(U/L)(xi-2yj+zk) Compute the mass-flow rate across a plane of area A that is perpendicular to the x axis and lies at x=3L. The fluid density is d. I know that the mass-flow rate, M, is calculated by: M=Double integration [d(u*n)]dA I am having trouble setting up the i

Deflection at a Slope Point

For the cantilever beam and loading shown, determine the deflection and slope at point B. Use E = 29,000,000 psi. Deflection a. 0.113 in b. 0.285 in c. 0.424 in d. 0.625 in Slope a. 0.0021 rad b. 0.0051 rad c. 0.0175 rad d. 0.0196 rad

What is the axial deformation in the link?

Each of the two vertical links BD has a uniform cross section 0.375 X 1.5 in. Determine the axial deformation and normal stress in each link for the loading shown. Determine the axial force in each link for the loading shown. Use E = 29 X 10^6 psi Axial deformation a. 0.00196 in b. 0.00392 in c. 0.00467 in d. 0.0

Determine the stress on a steel rod

The rod ABC is made of steel (E = 29 X 10^6 psi). Determine the normal stress in section BC. Determine the deflection at point B and C. See attached file for full problem description.

Determine the stress and critical load

A hollow brass rod is pin jointed and loaded in compression as shown. Knowing that the length L = 3 m, outside diameter D = 60 mm, and the wall thickness t = 10 mm, determine the critical load P. Use E = 105 GPa. Determine the normal stress at the critical load and what is the strain energy of the brass rod at the critical lo

Polar coordinate problem

After taking off, a helicopter climbs in a straight line at a constant angle B. Its flight is tracked by radar from point A. Determine the speed of the helicopter in terms of d, B, p and p dot. I know that in polar coordinates: v=r(p dot) I know I need to get r in terms of d, B, p and p dot. I have been trying different

Introductory Thermodynamics - rigid tank

A rigid tank with a volume of 2.5m^3 contains 5kg of saturated liquid-vapor mixture of water at 75 deg C. Now the water is slowly heated. Determine the temperature at which the liquid in the tank is completely vaporized. Also show the process on a T-v diagram with respect to saturation lines.

Hydrostatic Pressure and Forces

Determine the force due to hydrostatic pressure acting on the hinge of the gate shown. The fluid density is d and the width of the elliptical gate (out of the page) is 6H. (I have attached the picture provided) The answer is supposed to be: 21(pi)dg(H^3)/8