Molecular Physics | Thermodynamics Answers

3. A working substance undergoes a reversible non flow process during which P

= (-3V + 100) psia, where V changes from 10 ft3/min to 30 ft3/min. The change

of internal energy for the process is – 100 BTU/min. For a non-flow process,

determine a) work (BTU/min) b) heat transferred (BTU/min).

1. A water pump operating under steady flow conditions delivers 33 kgm/s of

water from initial pressure of 82 kPaa to a final pressure of 275 kPaa. The

diameter of the inlet pipe is 15 cm and the diameter of the discharge pipe is

10 cm. What is the steady flow work if Q=0 and density of water is 1000

kgm/m3?

The pressure in the pressurized water tank is measured by a multi-fluid manometer

with one end open to the atmosphere. Determine the absolute pressure of air in the

tank (pressure at point 1) assuming that the air pressure is uniform. The densities of

mercury, water and oil are 13,600 kgm/m3, 1000 kgm/m3, 850 kgm/m3, respectively. h1

= 20 cm, h2 = 30 cm and h3 = 46 cm

Barometric Pressure is 29.89 in Hg. Convert the following

a. 68 psig to mm Hg absolute

b. 100 kPag to psia

c. 1000 mm Hg absolute to kPag

d. 5 psia to in Hg vacuum

A 700 lbm rocket is accelerated at a rate of 20 ft/s2. What total force is required in lbf

if: a) the rocket is moving horizontally and without friction, b) the rocket is moving

vertically upward in a location where g = 31 ft/s2.

Four bodies are located in a region where g = 9.67 m/s2

.Body1 = 750 gm; Body2 = 4 poundals; body3 = 4.5 N and body4 = 32.2 lbf.

a) What is the total mass expressed in lbm?

b) What will be the total weight (lbf) if the bodies are located 15,000 ft above

the earth’s surface? (gravitational acceleration decreases by 0.003 ft/s2

for every 1000 ft ascent above sea level)

c) At what distance (miles) from the earth’s surface will these objects weigh

zero.

The block in figure reaches a velocity of 12m/s in 30m, starting from rest

Compute the coefficient kinetic friction between the block and the ground.

• 718 N
• P = 268 N

A heat engine is supplied with 278 k3/s of heat at a constant fixed temperature of 283°C and the best rejection takes place at 5°C The following results were reported (i) 208 klis are rejected, (ii) 139 klis are rejected, and (ii) 70 kJ/s are rejected Classify which of the results report a reversible cycle or irreversible cycle or impossible results

Water flows through a garden house with inner diameter 1.5 cm at a speed of 2.9 m/s. Calculate the speed of water escape from the nozzle if the opening is reduce to a diameter of 0.50 cm

A heater marked 60°c evaporates 6x10¯³ kg of boiling water in 60 seconds and what is the specific latent heat of vaporization of water in Jkg¯¹