Mechanical Engineering Answers

For an exhaust temperature of 54⁰c in a Rankine cycle, compare the heats supplied, the heats rejected, and the thermal efficiencies when at the beginning of isentropic expansion the steam is at a) 1.4Mpa and 315⁰c, b) 2.8MPa and 315⁰c. Note the variation of the efficiency.

given, pool volume 86.9m^3

hydraulic pressure= .00028733N/m

F=PxA = .0166N

1.    If the pool is built with 15 cm concrete on the bottom and 10 cm concrete walls, calculate the net weight of the pool structure for each half. What are the resulting net forces on each half of the pool? You’ll need to show a free body diagram with the direction of the forces shown.

2.    Based on your results, can you comment on the photo and conclude why one half is higher than the other? And can you guess what is the water level around the pool? There is not one easy answer for this last question, use your judgment.

The density of concrete is 2320 kg/m³

A refrigerator using R-134a is located in a 20 0 C room. Consider the cycle to be ideal, except that the

compressor is neither adiabatic nor reversible. Saturated vapor at -20 0 C enters the compressor, and the

R-134a exits the compressor at 50 0 C. The condenser temperature is 40 0 C. The mass flow rate of

refrigerant around the cycle is 0.2kg/s and the c.o.p is measured and found to be 2.3. Find the power

input to the compressor and the rate of entropy generation in the compressor process.

An ice making machine operates on the ideal vapor compression cycle, using R-134a. The refrigerant

enters the compressor as saturated vapor at 140kPa and leaves the condenser as saturated liquid at

700kPa. Water enters the ice machine at 13 0 C and leaves as ice -4 0 C. For an ice production rate of 9kg/h,

determine the power input to the ice machine.

What is the difference between the vice grip and a wrench in terms of

their structure and functions

Difference between Dynamic vibration and Static vibration

Need help with question 3 & 4

2. Convert all data to SI (metric) units: Determine the volume in liters and

in gallons for the pool volume. The pool has dimensions of 18’X35’, where

(’) is a symbol indicating a foot. The pool has a depth of 1 meter at one

end and 2 meters at the other end. We will assume that 50% of the pool

has a depth of 1 meter and the other 50% has a depth of 2 meters. All

height dimensions are from the pool deck surface and you can

approximate 3.3’ to be equal to 1 meter.

3. Assuming that the water level in the ground surrounding the pool is just

30 cm below the pool deck surface (a reasonable assumption during the

rainy season in South Florida), determine the hydraulic pressure for the 2

halves of the pool.

4. Using the surface areas of the 2 halves, calculate the hydraulic force on

each half.

The density of concrete is 2320 kg/m

Why do some technicians use Allen keys instead of self-tapping screws to fasten joint?

Design a V belt to transmit 8.5 kW power from a pulley rotating at 1500 rpm to a fan pulley to rotate at 500 rpm (neglecting slip). The fan is to be used for 24 hours a day and space does not permit to have center distance more than 1,100 mm. Select V belt and give details of your calculations.