Explore BrainMass

Mechanical Engineering

Tire Explosion Prediction Math Model

You witnessed the failure of a nylon rim which exploded injuring the person filling the tire with air. Develop a documented mathematical model that predicts the time required to reach a specific pressure. Your results are to be tabulated and plotted. Specifically predict the time to change from 100 kPa to 800 kPa. Assume the pro

Determine the Radius of Curvature

For the composite bar indicated (see attachment), determine the radius of curvature caused by the couple of moment 70 Nm. a) 9.16 mm b) 12.73 mm c) 11.87 mm d) 10.41 mm

Largest Allowable Square Cross Section

Determine the largest allowable square cross section of a steel shaft of length 6 m if the maximum shearing stress is not to exceed 135 MPa when the shaft is twisted through one complete revolution. Use G = 77.2 GPa.

Determine the maximum allowable stress

Knowing that, for the plate shown (see attachment), the allowable stress is 24 ksi, determine the maximum allowable value of P when r = 3/4 in. a) 35.42 kips b) 12.89 kips c) 43.27 kips d) 25.71 kips

Simple Vapor Power Plant

Steam enters the turbine of a simple vapor power plant with a pressure of 160 bar and a temp of 560 C and expands adiabatically to 0.08 bar. The isentropic turbine efficiency is 85%. Saturated liquid exits the condenser at 0.08 bar and the isentropic pump efficiency is 85%. Determine a) enthalpy of steam leaving the turbine

Mechanical Vibration and Springs

The machine shown in the figure is rigidly anchored on a rigid concrete block and the mass of both is 3000 kg. The block has height h = 1 m and square horizontal section with a = 1.2 m and is supported at the corners by 12 springs of stiffness k = 2000 N/m. i) Derive the equations of motion of the system using both Newton's

Mechanical Vibration

The machine shown in the figure is rigidly anchored on a rigid concrete block and the mass of both is 3000 kg. The block has height h = 1 m and square horizontal section with a = 1.2 m and is supported at the corners by 12 springs of stiffness k = 2000 N/m. Solve only the second part: (see attachment for diagram) ii) Find t

Range of Velocity for the pitching wedge

A pitching wedge a golfer is using gives the ball an initial angle of 50 degrees, what range of velocities (Vo) will cause the ball to land within 3 ft. of the hole? (the hole is 30 ft. from golfer). Assume that the hole lies on the plane of the ball's trajectory. I need help setting this problem up to start.

Rate of Heat Generation

A fillet weld is used to join two medium carbon steel plates each having a thickness of 5.0mm. The plates are joined at a 90 degree angle using an inside fillet corner joint. The velocity of the welding head is 6mm/sec. Assume that the cross section of the weld bead approximates a right isosceles triangle with a leg length of 4.

DB - Find the capacity of a cylindrical tank

1. Find the capacity of a cylindrical tank that is 250 feet in diameter and 30 feet high? 2. In the above problem, what is the capacity if the tank is 75% full, and what is the capacity in gallons? 3. If 50 pounds of chlorine are mix with 100 pounds of water, what is per cent chlorine solution that is made? 4. Find

Calculating Modulus of Rupture

Please help with the following problem. See the attached wood block diagrams. If a break load of 250 lbs. is applied to the first wood specimen, how do I determine the Moment of Inertia and calculate the Modulus of Rupture? The only difference between the specimens per the attached diagram is that a 1/4" x 1/4" key-way is

Future Value of sums of money over eight years

Your rich godfather has offered you a choice of one of the three following alternatives: $10,000 now; $2,000 a year for eight yeaers; or $24,000 at the end of eight years. assuming you could earn 11 percent annually, which alterantive should you coose? If you could earn 12 percent annually, would you still choose the same altera

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?

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

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

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.

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.

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

Hydrostatic Relation Empirical Formulas

An empirical formula relating pressure and density for seawater w/ temperature held constant is: p/pa = (k+1)(q/qa)^7 - k where p= pressure pa = pressure at the surface k = dimensionless constant q = density qa = density at the surface Using the formula in the

Number sentences

Komodo dragons are the largest lizards known to man. A 250-pound dragon can eat enough food to increase it body weight by 1/2. Which number sentence could be used to find w, the weight of a komodo dragon after increasing it body weight by 1/2? If eight people share in eating 3/4 of a quart of ice cream, how much will each per