Questions
You are the manager of a healthcare facility that is considering different payment options for buying...

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)...

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?

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...

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...

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

18- The choice of chiller determines how the facility is prepared. Examples of parameters that determine...

18- The choice of chiller determines how the facility is prepared. Examples of parameters that determine the chiller are:
(a) Electrical requirements
(b) Ease of installation (air-cooled chillers are easier to set up)
(c) Location or available space
(d) Comfort or process cooling
(e) All of the above

19- Ventilated outdoor air can be used:
(a) for cooling of the buildings throughout the year in all locations
(b) for cooling of the buildings during many days of the year in most of the locations (c) greater potential for cooling of buildings in hot and humid areas
(d) greater potential for cooling of buildings in hot and dry areas
20- State which of the following statements are TRUE?
a) For effective utilization of outdoor air, both natural and mechanical ventilation
should be used in a building
b) Design of windows and other openings in the buildings plays a major role in
natural ventilation
c) For maximum airflow rate, the openings should be as close to the neutral pressure
level as possible
d) All of the above.
21- In comfort-cooling applications, cooling loads are often satisfied by air handlers equipped with coils to transfer heat from the conditioned space air to circulating
chilled-water. Heat transferred ways:
a) Three-wayvalve
b) Two-wayvalve
c) Variable-speed pump
d) All of the above.
from the loads can be controlled in a number of
22- An air handler supplies 5,000 CFM (2.36m3/s) at a temperature of 13°C. The air handler was designed for 1,000 CFM of outside air at 31°C DB and 26°C WB. The remaining return air from the space is at 25 °C DB and 55% relative humidity. What are the entering conditions of the air into the coil, in DB and WB?
(a) 26 C ?BT, 20 C ?BT
(b) 26 C ?BT, 15 C ?BT
(c) 29.5 C ?BT, 23.5 C ?BT (d) 29.5 C ?BT, 24 C ?BT
23- In variable air volume systems:
(a) In single duct, variable air volume systems, the supply air flow rate remains
constant, but the temperature of the supply air is varied depending upon the load (b) Variable air volume systems generally consume less power compared to constant
volume systems
(c) Variable air volume systems occupy less space compared to constant volume
systems
(d) Variable air volume systems always ensure adequate ventilation and good room
air distribution

24- For air-water system, Which of the following statements are TRUE?
(a) An air-water system uses both air and water in the thermal distribution system (b) In an air-water system, all the latent load on the building is handled by the
primary air only
(c) In an air-water system, the cooling coil kept in the conditioned space operates
under dry conditions
(d) Compared to all water systems, an air-water system is difficult to maintain
25- For fan coil unit ,Which of the following statements are TRUE?
(a) A fan coil unit is used with all water systems only
(b) A fan coil unit can be used either with an all water system or with an air-water
system
(c) It is possible to control the cooling capacity by controlling either liquid flow rate
or air flow rate in a fan coil unit
(d) A fan coil unit used in an all water system requires a provision for draining the
condensed water
26- For a convector, Which of the following statements are TRUE?
(a) In a convector, heat transfer takes place by forced convection
(b) Convectors are commonly used for heating applications
(c) In a radiator, heat transfer takes place by both radiation and convection (d) A unit ventilator is a fan coil unit with a provision for fresh air entry
27- For Small unitary systems, Which of the following statements are TRUE?
(a) Small unitary systems have air cooled condensers, while larger systems can be
either air cooled or water cooled
(b) A split type room air conditioner should be used when the room does not have an
exterior wall
(c) A split type air conditioner is more reliable compared to a window air conditioner (d) It is possible to provide fresh air in a window air conditioner, whereas this is not
possible in a split air conditioner

In: Mechanical Engineering

Report About (( Lift Mechanism )) 1- Abstract 2-Introduction 3- Model Description 4- Discussion 5. Conclusions...

Report About (( Lift Mechanism ))

1- Abstract 2-Introduction
3- Model Description 4- Discussion
5. Conclusions 6. References

! DONT COPY IT Please !

In: Mechanical Engineering

At a point in a bracket, the stress on two mutually perpendicular planes are 100 N/mm2...

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:

  1. Magnitude and direction of the resultant stress on plane making an angle of 200 with the plane of the first stress.
  2. Maximum shear stress and location of its plane.

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...

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,...

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

A cylindrical shell is 3 m long; 1 m in diameter and the thickness of metal...

  1. A cylindrical shell is 3 m long; 1 m in diameter and the thickness of metal is 10 mm. It is subjected to an internal pressure of 150 N/cm2. Calculate the change in dimensions of the shell and the maximum intensity of shear stress induced. Given E= 200 GPa and Poisson’s ratio =0.3.

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...

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.

In: Mechanical Engineering

A uniform supersonic airflow traveling at passes over a wedge (as Figure). An oblique shock, making...

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

Three devices, X, Y and Z are connected in series to a hydraulic pump. Device X...

  1. Three devices, X, Y and Z are connected in series to a hydraulic pump. Device X operates at 0.4 MPa, device Y operate at 0.8 MPa and device C operates at 1 MPa. Sketch the arrangement and placed a pressure indicator readings. (CO2,PO2,C3)

  1. Three devices, X, Y and Z are connected in parallel to a hydraulic pump. Device X operates at 0.4 MPa, device Y operate at 0.8 MPa and device C operates at 1 MPa. Sketch the arrangement and placed a pressure indicator readings. (CO2,PO2,C3)

In: Mechanical Engineering

Air enters an air-conditioning system that uses refrigerant-134a at 30°C and 70 percent relative humidity at...

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