Which type of motor is hydraulically balanced so as not to have buckling forces on the drive shaft.
(A) Gear
(B) Palettes
(C) Pistons

And Why?

The pressure compensator in which type of hydraulic piston motor is used.
(A) Axial
(B) Inclined axis
(C) Alternative

And Why?

The pressure plate is used in the manufacture of the motor of:
(A) Gear
(B) Palettes
(C) Pistons

And Why?

Thank you for your time, have a nice day :)

0.5 kg of a gas at temperature t₁=20?C and pressure p₁=0.1 MPa was contained in a cylinder with a piston. The gas was compressed (polytropic process) and a ratio of heat exchanged during the process to the work of compression was ¼. Find the final temperature and pressure of the gas if 15 KJ of heat was transferred to the surroundings. Specific heats at constant volume and pressure were 654.67 J/Kg/K and 897.64 J/kg/K, respectively.

Air undergoes a polytropic process in a piston–cylinder assembly from p1 = 1 bar, T1 = 295 K to p2 = 7 bar. The air is modeled as an ideal gas and kinetic and potential energy effects are negligible. For a polytropic exponent of 1.4, determine the work and heat transfer, each in kJ per kg of air, (1) assuming constant cv evaluated at 300 K. (2) assuming variable specific heats.

Determine whether the following statements are correct (y) or not (n): and explain why..

( ) A system have a higher second law efficiency than the first law efficiency during a process

( ) It is impossible that the energy of one isolated system increases

( ) Adding moisture is the ONLY way to obtain saturated air from unsaturated air

( ) A Piston Cylinder device contains air. During a reversible, isothermal process the entropy of the air will never decrease.

Air undergoes a polytropic process in a piston–cylinder assembly from p₁ = 1 bar, T₁ = 295 K to p₂ = 3 bar. The air is modeled as an ideal gas and kinetic and potential energy effects are negligible.
For a polytropic exponent of 1.2, determine the work and heat transfer, each in kJ per kg of air,
(1) assuming constant c_v evaluated at 300 K.
(2) assuming variable specific heats.

Assume that you have a cylinder fitted with a movable piston and enclosing a fixed amount of gas. Provide a mathematical proof to your answer for each of the following cases.
​A. What would happen to the gas pressure inside the cylinder if you decrease the volume to one-fourth the original volume while holding the temperature constant?
​B. What would happen to to the gas volume inside the cylinder if the pressure is doubled and the Kelvin temperature is doubled?

Air undergoes a polytropic process in a piston–cylinder assembly from p1 = 1 bar, T1 = 295 K to p2 = 3 bar. The air is modeled as an ideal gas and kinetic and potential energy effects are negligible. For a polytropic exponent of 1.6, determine the work and heat transfer, each in kJ per kg of air, (1) assuming constant cv evaluated at 300 K. (2) assuming variable specific heats.

Thirty-six grams of air in a piston–cylinder assembly undergo a Stirling cycle with a compression ratio of 7.5. At the beginning of the isothermal compression, the pressure and volume are 1 bar and 0.03 m³, respectively. The temperature during the isothermal expansion is 1200 K.


Assuming the ideal gas model and ignoring kinetic and potential energy effects, determine:

(a) the net work, in kJ.

(b) the percent thermal efficiency.

(c) the mean effective pressure, in bar.

5 kg of saturated liquid water at 10 bars is contained in a piston-cylinder assembly and undergoes two processes. process 1-2: heated at constant pressure until it is saturated vapor. process 2-3: cooled as it is compressed at constant volume until it reaches 110 degrees celsius. determine the overall work and heat transfer for these processes. Hint: Must used linear interpolation from values in the correct Water tables.

1) The daily demand, D, of sodas in the break room is:

i) Find the probability that the demand is at most 2.
ii) Compute the average demand of sodas.
iii) Compute SD of daily demand of sodas.

2) From experience you know that 83% of the desks in the schools have gum stuck
beneath them. In a random sample of 14 desks.
a) Compute the probability that all of them have gum underneath.
b) Compute the probability that 10 or less desks have gum.
c) What is the probability that more than 10 have gum?
d) What is the expected number of desks in the sample have gum?
e) What is the SD of the number of desks with gum?

3) The number of customers, X, arriving in a ATM in the afternoon can be modeled
using a Poisson distribution with mean 6.5.
a) Compute P(X<3).
b) Compute P(X>4).
c) SD of X.