You are the manager of a healthcare facility that is considering different payment options for buying supplies for your facility. The annual charges for these supplies is $10,000 and the vendor is offering you three payment options to consider.
option 1: 3% discount if you make the full payment in 30 days.
option 2: quarterly payments at the beginning of each quarter with a service charge of $100 per quarter.
option 3: monthly payments at the beginning of each month with a service charge of 3% for each monthly payment.
Q1: Which of these three options provides the best value for money? Why?
Q2: Payments for these supplies are made from your bank account which has a current balance of $30,000 and earns monthly interest of 0.2%.
a. Which of these three options now provides the best value for money?
b. At what interest rate would you be indifferent between Options 1 and 2?
c. At what interest rate would you be indifferent between Options 2 and 3?
d. Consider the ending balances under each of these three options for interest rate ranging from 0.0% to 2.0%. Develop data tables to compute the ending balances for this range of interest (consider interest increments of 0.2%). Depict your results in a line graph.
In: Mechanical Engineering
Assuming standard atmospheric pressure and tdb=25 C and 90% RH. Compute (a) dew point temperature (b) specific humidity (c) enthalpy (d) wet bulb temperature
In: Mechanical Engineering
Joining dissimilar metal in arc welding is a difficult task. Explain why?
In: Mechanical Engineering
There are 5000 CFM of outdoor air with a temp of 40F 35Fwb heated and humidified under steady-flow conditions to a final temp of 70F and 40%RH a)find the mass of water vapor added to each pound mass of dry air b) if the water is supplied at 50F how much heat in Btu/min.
In: Mechanical Engineering
An ACME double-threaded power screw has 45 mm major diameter, a pitch of 5 mm and thread angle 2α=29°. A vertical load on the screw reaches a maximum of 8.5 kN. The coefficients of friction are 0.05 for the thread and 0.1 for the collar. The frictional diameter of the collar is 65 mm. a) Find the efficiency of the power screw. b) Is this power screw self-locking? Explain why
In: Mechanical Engineering
In: Mechanical Engineering
In: Mechanical Engineering
At a point in a bracket, the stress on two mutually perpendicular planes are 100 N/mm2 (tensile) and 50 N/mm2 (tensile). The shear stress across the planes is 80 N/mm2. Find using Mohr stress circle or otherwise calculate:
c. Principal stresses and the location of principal planes
In: Mechanical Engineering
Design any pneumatic system of any industrial application with
at least 3 outputs.
Please describe the components used.
Example: Bottle Sorting and Labelling: The three outputs can be to
sort the bottle by color or size then Seal the Bottle and later Put
it in a box. This is just an example...you can use any.
In: Mechanical Engineering
A long, cylindrical, electrical heating element of diameter D=
10 mm, thermal conductivity k= 240 W/m·K, density ρ= 2700
kg/m3, and specific heat cp= 900 J/kg·K is installed in
a duct for which air moves in cross flow over the heater at a
temperature and velocity of 27°C and 15 m/s, respectively.
(a) Neglecting radiation, estimate the steady-state surface
temperature when, per unit length of the heater, electrical energy
is being dissipated at a rate of 1500 W/m.
(b) If the heater is activated from an initial temperature of 27°C,
estimate the time required for the surface temperature to come
within 10°C of its steady-state value.
Evaluate the properties of air at 450 K.
What is the value of the Reynolds number?
Re = 4613.05 (correct)
What is the value of the average Nusselt number?
not sure
What is the steady state temperature, in K?
got it correct
=666.96 K
What is the value of the Biot number?
Bi =0.0027
got correct
How long does it take for the element to come within 10°C of the steady state temperature, in s?
t= 168.21 correct
Knowing the steady state temperature, what is the actual value of the film temperature that should be used to find the air properties, in K? (Do not redo the problem.)
Tf=
(not sure )
In: Mechanical Engineering
b. Two shafts of the same material and same lengths are subjected to the same torque. If the first shaft is of a solid circular section, the second shaft is of hollow circular section, whose internal diameter is 2/3 of the outside diameter and the maximum shear stress developed in each shaft is the same, compare the weights of the shafts
In: Mechanical Engineering
heat transfer question, show equations, assumptions, calculations and steps clearly. will give thumbs up rating if solved correctly in 50 minutes
Write the Heat Diffusion Equation (HDE) in Cartesian coordinates and explain the meaning of every term.
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A uniform supersonic airflow traveling at passes over a wedge (as Figure). An oblique shock, making an angle of 40° with the flow direction, is attached to the wedge under these flow conditions. If the static pressure and temperature in the uniform flow are 20k Pa, -10 °C, respectively. Determine the static pressure and temperature behind the wave, the Mach number of the flow passing over the wedge, and the wedge half-angle.
In: Mechanical Engineering
In: Mechanical Engineering
Air enters an air-conditioning system that uses refrigerant-134a at 30°C and 70 percent relative humidity at a rate of 4 m3/min. The refrigerant enters the cooling section at 700 kPa with a quality of 20 percent and leaves as saturated vapor. The air is cooled to 20°C at a pressure of 90kPa .
Determine the rate of dehumidification m˙w= kg/min (Round to five decimal places)
Determine the rate of heat transfer Q˙out= kJ/min (Round to two decimal places)
Determine the mass flow rate of the refrigerant m˙R= kg/min (Round to three decimal places)
In: Mechanical Engineering