Explore BrainMass
Share

Mechanical Engineering

Angular acceleration/velocity of a bar

Bar ABCD is guided by two blocks at B and C moving in slots as shown. Block B moves downward at a constant speed of Vb = 10ft/s. Using the method of instantaneous center of zero velocity, determine (a) the angular velocity of the link, (b) the velocity of the block C at the instant when theta = 35 degrees, and (c) the angular ac

Water is the working fluid in an ideal Rankine cycle.

Water is the working fluid in an ideal Rankine cycle. Saturated vapor enters the turbine at 18 MPa. The condenser pressure is 6 kPa. How to determine the quality of the fluid at the turbine exit, and the heat transfer to the steam passing through the boiler in kJ per kg of steam flowing? The enthalpy of the steam entering the

Heat pump for house

Ever wonder if you can build a machine to heat up your house using the heat from the outside environment? Well you'll need to start with the heat pump concept. In this example, you'll learn how to determine the maximum theoretical coefficient of performance for a heat pump operating at steady state between a dwelling at 70 de

Specific and Relative Humidity

You have a box that contains 100 kmoles of dry air and 1 kmole of water vapor. The contents are at a pressure of 100 kPa. Someone says that they need to have the enthalpy of the mixture to be 63.8 kJ/kg dry air where 0 degrees Celsius is the reference temperature at which enthalpy is zero. Find the following: a.) The Specif

A Vapor-Compression Heat Pump System

A vapor-compression heat pump system uses R-134a as the working fluid. The refrigerant enters the compressor at 0.24 Mpa, 0 degrees Celsius, with a volumetric flow rate of 0.6m^3/min. The compression process is adiabatic to 0.9 MPa, 60 degrees Celsius, and saturated liquid exits the condenser at 0.9 MPa. Find the following:

Water is the working fluid in an ideal Rankine cycle.

Water is the working fluid in an ideal Rankine cycle. Saturated vapor enters the turbine at 18 MPa. The condenser pressure is 6 kPa. How do I determine the quality of the fluid at the turbine exit, and the heat transfer to the steam passing through the boiler in kJ per kg of steam flowing. The enthalpy of the steam entering the

Determining Feasibility

At steady state, a new power cycle is claimed by its inventor to develop 6 horsepower for a heat addition rate of 400 Btu/min. If the cycle operates between reservoirs at 2400 and 1000 deg R, is the claim feasible?

Volumetric Flow Rate

Air enters a 0.6 m diameter fan at 16 deg C, 101 kPa, and is discharged at 18 deg C, 105 kPa, with a volumetric flow rate of 0.35 m^3/s. Assuming ideal gas behavior, how do I determine for steady-state operation, the mass flow rate of air, in kg/s? How do I figure the volumetric flow rate at the inlet, in m^3/s and the inlet ve

Determine the Mass of Ammonia

Ammonia is stored in a tank with a volume of 0.21 m^3. How do I determine the mass, in kg, assuming saturated liquid at 20 deg C.

Find the Temperature of the Refrigerant

A closed vessel with a volume of 2 ft^3 contains 5 lb of Refrigerant 134a. A pressure sensor in the tank wall reads 71.39 lbf/in.^2 (gage). If the atmospheric pressure is 14.4 lbf/in.^2 how do I find the temperature of the refrigerant, in deg F?

Determine the Final Velocity

An object whose mass is 1 lb has a velocity of 100 ft/s. How would I determine the final velocity, in ft/s, if the kinetic energy of the object decreases by 100 ft*lbf? What would be the change in elevation, in ft. associated with the 100 ft*lbf change in potential energy if g=32.0 ft/s^2?

Turbine Thermal Efficiency

Steam @ 10 MPa, 600 degrees celcius enters the first-stage turbine of an ideal Rankine cycle with reheat. The steam leaving the reheat section of the steam generator is @ 500 degrees celcius, and the condensor pressure is 5 kPa. If the quality at the exit of the second-stage turbine is 90%, determine the cycle thermal efficien

Wireless Networks - Output Encoder Determination

1) Consider the rate r = ½ in the convolution encoder shown below. Find the encoder output (Y1, Y2) produced by the message 10111. Assume that the initial state is zero. 2) Find the state diagram for the attached.

Amplitude of Motion; System Response Equation

1. The spring - mass system shown in figure 1 (see attached) is subjected to a triangular force for the time duration td. Determine... (a) the amplitude of the motion at time ... (b) the system response equation after time .... Please see attachment for complete question.

Mechanics of Materials

Question: Two full-size 2x6 inch planks are connected as shown by lag screws to form a beam which is subject to a vertical shear of 400 lb. Knowing that the allowable shearing force is 360 lb in each lag screw, how would I determine the largest permissible longitudinal spacing (s) of the lag screws, and the maximum shearing stre

Mechanics of Materials 1678

The rigid bar ABCD is suspended from three identical wires as shown. Knowing that a=b, how would I determine the tension in wires A, B, and D caused by the load P applied at C?

Mechanics: Bending Moment

Question: Semicircular grooves of radius r must be milled in the top and bottom portions of a steel bar as shown in the attached file. Using an allowable stress of 100 MPa, how do I determine the largest bending moment which may be applied to the bar shown when the radius of the semicircular grooves is 20 mm?

Rigid Bodies and Newton's Second Law of Motion

The wheel and axle system shown attached in Figure Q2 supports a free hanging mass of 360g. The mass is initially a distance of 2.16m above the floor level when it is released causing the mass to hit the floor 6.2s later. The mass of the wheel and axle system is 40.2kg and its effective radius of gyration is equal to 2.8cm. (

Problems of Velocity, Angular Velocity and Acceleration in Trains and Wheels

Question 1: A train accelerates uniformly along a straight track and passes three trackside markers. The distance between the first two markers is equal to 0.25 km and between the second and third the distance is 0.4km. The train takes 26.6 seconds to travel between the first two markers and its speed as it passes the second ma

Force Required to Punch a Hole into an Aluminium Sheet

Question 4: (a) Calculate the force required to punch out a rectangular hole 100m x 50mm in a 2mm thick aluminium sheet. The ultimate strength in shear is 125 MN/m^2. (b) If the maximum force which can be exerted by the press is 45kN, what is the greatest thickness that can be punched out? Question 5: Two co-axial sha

Effect of Direct and Shear Forces on a Steel Specimen

Question 1: The attached load/extension values were found when a steel specimen was tested to destruction. Calculate: 1. The stress at the limit of proportionality 2. The yield stress 3. The ultimate tensile stress (UTS) 4. Young Modulus of Elasticity 5. Percentage Reduction in area 6. The percentage elongation 7.

Analyze the Planner Equilibrium

The roof truss shown attached is roller and pin-joint supported at the right-hand and left-hand ends respectively and carries loads of 10kN, 8kN and 12 kN as shown. Show that the structure is stable and determine, using the method of resolution of forces at the joints, the magnitude and nature of the forces acting in each of

Radiation

5. Determine the fraction of the radiation leaving the base of the cylindrical enclosure shown attached that escapes through a coaxial ring opening at its top surface. The radius and the length of the enclosure are r_1 = 10cm and L = 10cm, while the inner and outer radii of the ring are r_2 = 5 cm and r_3 = 8cm, respectively.

Weld analysis

Two steel plates are joined with a butt weld using a weld throat h of 3/8 in. and the length of weld 1 of 4in. How do I determine the shear stress in the weld for a shearing force of 15000 lbf?

Midrange and amplitude components

A shaft is subjected to a completely reversed bending stress such that Xmax=40kpsi and Xmin=-40kpsi. How do I determine the midrange component and the amplitude component? (X=sigma)

Endurance limit

A steel rod AISI 1018 has the rotating bending specimen's endurance limit of 32.2kpsi. How do I determine the endurance limit for the part if the Marin modifying factors are: ka=0.887, kb=1, kc=0.889, kd=ke, kf=1?

Endurance limit

A steel rod AISI 1040 has the ultimate tensile strength (Sut) of 113kpsi. How do I determine the rotating bending specimen's endurance limit at 10^6 cycles?

Principal stresses

The state of plane stress at a point in a member is zx=-20MPa, zy=90MPa, txy=60MPa. How do I find the principal stresses zx and zy?