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Mechanical Engineering

Manufacturing processes factors

1. Explain the factors involved in selecting the appropriate type of abrasive for a particular grinding operation. 2. What are the consequences of allowing the temperatures to rise during grinding? (Q. 25.38). 3. What are the implications of using a smaller abrasive grain size (higher grit number) in a bonded grinding wheel?

Moment of Inertia Problems

The three problems attached having to do with moment of inertia of things like a yo-yo. I need help setting them up. Please send explanations with the answer so I can see how your answer was achieved.

Mass of Inertia and Angular Acceleration

1. Two slender rods are welded together at right angles and released from rest as shown. The two welded bars rotate freely around point C. Each bar is 10 lbs and is 1.5 ft long. At release, what is the acceleration magnitude of point B? 2. A vertical 0.2-meter-long slender bar with a uniform cross section is released from res

Manufacturing Processes

Please answer the following questions: Certain manufacturing processes have the following characteristics described below. Please characterize the process in terms of : Type of process, state of workpiece material and the type of process energy used. 1. A metal is cast into a mold and solidifies 2. A metal bar is reduce

Mechanical Vibration Analysis

For this two degree fo freedom model, how do I find the matrix equation of motion? How do I find the value of the modal ratios if m1=m2=m, k1=k and k2=3k? If a force of 25sin3t is applied to m2, how do I find the value of the response if m1=m2=1 slug, k1=10lb/ft and k2=30lb/ft?

Mechnical Vibration Analysis

I have a mass-spring-damper system that is tested to determine the value of the viscous damping coefficient c. Assume k=10lb/ft and m=2 slug. The vibrational amplitude is observed to decrease to 33% of its initial value after two consecutive cycles. How do I deduce the value of the logarithmic decrement? How do I deduce the v

Mechanical Vibration Analysis

How do you find the equation of motion for an idealized model? For this model how do you find the periodic time (time in sec) and the natural frequency (rad/sec)? Please see attached for diagram.

Turbomachinery and Reaction Turbines

1) Steam at 15 bar and 350 degrees C is expanded through a 50% reaction turbine to a pressure of 0.14 bar. The stage efficiency is 80% for each stage and the reheat factor is 1.05. The expansion is to be carried out in 10 stages and the required power is 6000 kW. Calculate the steam flow required, assuming that the stages all de

Turbomachinery: Reaction Turbines

Please help with the following problem. Sketch the fully annotated velocity triangles for a Parsons turbine stage. Use your sketch to show that the specific work produced per stage is given as w_stage = (C_b)^2 [1 + 2(f/C_b)(cot(B_1))]. At a particular stage of a Parsons reaction turbine, the mean blade speed is 60 m/s an

Turbomachinery: Impulse Turbine

1) The steam from the nozzles of a single wheel impulse turbine discharges with a velocity of 600 m/s at an angle of 20 degrees. The blade wheel rotates at 3000 rev/min and the mean blade radius is 590 mm. The axial velocity of the stream at the exit from the blades is 164 m/s and the blades are symmetrical. Sketch the annota

Mass Moment of Inertia and Translational Motion

1. Calculate the mass moment of inertia about the x axis. The total mass of the object is 13 kg. 2. The plate with two holes is made of steel with a density of 7800 kg-m3. The radius of each hole is 5 cm. Determine its mass moment of inertia about the z-axis. 3. Determine the mass moment of inertia about the y axis. The t

Moment of Inertia and Translational Motion

1. A four-wheel truck that has a mass of 5,000 kg accelerates forward. The coefficient of friction for the front and back wheels is 0.2 and 0.4, respectively. What is the acceleration of the truck? Assume that the friction force on both the front and rear wheels are at a maximum and both are about to slip. 2. Each of the 2 b

Turbomachinery: Impulse and Reaction Turbines

1. An impulse air turbine rotor with a blade speed (U) of 300 m/s is measured to have a relative rotor inlet velocity (W_1) of 750 m/s at an angle of 69 degrees and an outlet relative velocity (W_2) of 660 m/s. Th temperature and pressure in the rotor are 375 K, 0.83 bar. Calculate the rotor efficiency, rotational speed and powe

Calculating the Second Moment of Area

It is necessary to design a square-section composite bar that will withstand an applied load without deflecting more than a specified amount.The design specification for the bar, including its dimensions and loading criteria, is given below. Using the formula below, calculate the second moment of area of the bar and use this

Plot Curve for Amplitude of Vibration; Determine Amplitude

A schematic of a horizontal shaker is shown in figure 1 {see attachment}. The shaker consists of a mass supported on four thin, rectangular springs. The springs are L=200mm long, w=50mm wide and t=4mm thick. The Young's modulus for the springs is 200 GPa. The mass is coupled to the ground via a damper with damping factor C=894Ns

Solve for Force (Engineering Dynamics)

Two forces act on a slender bar that is pinned at (see attachment). The horizontal reaction at 0 is 5 lb to the right, the force F in lb is closes to which answer choise? a) 25 b) 30 c) 15 d) 27 *Please see attachment for equations and diagram

Dynamics Problem - Backspin (Friction, Velocity)

A 1.2ft diameter ball is thrown onto a rough surface, such that it has a velocity of 6ft/s and a backspin angular velocity of w. If it is to stop backspinning at the same instant as the velocity is 0, the backspin w in rad/s is what? HINT: The answer is independent of the mass and coefficient of friction. a. 17.8 b. 22.0 c. 2

Calculating maximum velocity, displacement and stretch

The pair of blocks, which are connected by a cord, are released from rest when the spring is unstretched. The static and kinetic coefficients of friction are .2 and .1, respectively. The following things are to be found using the work-energy methods: 1) Maximum Velocity of the blocks 2) Stretch of the spring at the maximu

Thermodynamics Problem: Heat Pump

Hi, I am confused about how to answer the following question. Any assistance would be appreciated. Question: A heat pump with a COP (coefficient of performance) of 2.8 is used to heat an air-tight house. When running, the heat pump consumes 5 kW of power. If the temperature in the house is 7 degrees Celsius when the heat pum

Combustion Reactions and Thermochemistry

Liquid Octane at 25C, 1 bar is burned with air at 500K in a steady flow combustor. The products of combustion are cooled to 1400K, 1 bar and have the following volumetric analysis on a dry basis: 10.7% CO_@; 3.6% CO; 5.3% O_2 and 80.4% N_2. Determine the percentage excess air supplied, the dewpoint of the products and the heat t

Strain, Force and Distance

A particular grade of Nitinol SMA is capable of upto 6% strain recovery and develops an internal restoration stress of upto 300 MN m-2. Estimate the amount of force and distance of travel that could be triggered by warming a rod(20mm long,1mm diameter) of this material that had been permanently stretched(6%strain) when cold.

Pressure Cooker and Mass Flow Rate

Steam is leaving a pressure cooker whose operating pressure is 30 psi. It is observed that the amount of liquid in the cooker has decreased by 0.4 gal in 45 minutes after the steady operating conditions are established, and the cross-sectional area of the exit opening is 0.15 in^2. Determine (a) the mass flow rate of the steam a

Rate of Evaporation

Water is to be boiled at sea level in a 30-cm-diameter stainless steel pan placed on top of a 3-kW electric burner. If 60% of the heat generated by the burner is transferred to the water during boiling, determine the rate of evaporation of water. See Figure 2-39 attached. Please show steps.Thanks.

Superheated Water Vapour

Superheated water vapour at 180 psia and 500 degrees Farenheit is allowed to cool at a constant volume until the temperature drops to 250 degrees Farenheit. At the final state, determine: (a) the pressure (b) the quality (c) the enthalpy. Also, show the process on a T-v diagram with respect to saturation lines.

Boundary Layer Theory and Turbulent Flow in Pipes.

a) Calculate the power required to overcome the skin friction drag on the keel of a sailing dingy moving through water at 2m/s. The keel projects 0.8m into the water and it is 0.4m wide. Assume that the keel is a smooth flat rectangular plate and that transition from laminar to turbulent flow occurs instantaneously at Re = 4*10^

Cylindrical Pressure for Frictionless Piston Device

A gas is contained in a vertical, frictionless piston cylinder device. The piston has a mass of 4 kg and cross-sectional area of 35 cm^2. A compressed spring above the piston exerts a force of 60 N on the piston (as seen in Figure P1-73 attached). If the atmospheric pressure is 95 kPa. determine the pressure inside the cylinder.

Thermodynamic Equilibrium

For a system to be in thermodynamic equilibrium, do the temperature and the pressure have to be the same everywhere? Explain.

Assignment Question 3 in Applied Mechanics

Fig. Q3 shows a rigid light beam which is hinged at O to a wall. The beam carries a point mass of m at the free end. The beam is connected at its mid-point to a spring (stiffness k) which is also connected to a support that moves with a vertical motion y = Y sinwt. A damper (coefficient c) connects the mid-point of the beam to a

Tank flow rate

With the valve closed, water flows from tank A to tank B as shown in the attachment. What is the flow rate into tank B, when the valve is opened to allow water to flow into tank C also? Neglect all minor losses and assume that the friction factor is 0.02 for all pipes.