Does systematic error vary during repeated readings? What is the relationship between systematic error and the sample size?
In: Mechanical Engineering
In: Mechanical Engineering
What is the difference between SMC-R50 composite and fabric reinforced composites?
I know SMC uses random fiber orientation, is there a random fiber fabric?
Thanks
In: Mechanical Engineering
If a golf ball were dropped from a significant height and the force of Drag is modeled by Fd=0.0057*V-0.0106, where V is the velocity in m/s the Fd is the force of drag in N. The mass of the golf ball is 0.0455 Kg.
h. How high will the golf ball bounce after the 5th impact with the concrete surface ignore drag force?
i. If drag was included for G and H what type of analysis technique would be needed
In: Mechanical Engineering
Water is discharged from a pipe outlet at a rate of 60l/s at 120.8 kPa absolute pressure. All pipes are 15 cm in diameter with a total length of 200 m. The total pipe length on the suction side is 10.8 m. Both reservoirs are big. The water surfaces are exposed to the atmosphere and the difference in their levels is 9 m.
Pipeline friction head loss is 0.086 m per meter length of pipe. On the suction side, fitting loss is 1.3 m while on the delivery side, fitting loss varies with the square of the velocity with K = 1.0.
a) Find the height of the water level above the pipe outlet in the receiving reservoir (m).
b) Find the total head loss of the system (m).
c) What is the hydraulic power (kW)?
d) The water to be pumped has a vapour pressure of 2335 N/m2. The cavitation parameter, s = 0.12. Find the maximum pump height possible above the surface of the water in the supply reservoir (Show clearly the calculation of all heads involved).]
(Atmospheric pressure = 101.3 kPa).
In: Mechanical Engineering
The stream function ?? in a two-dimensional flow field is given as ?? = 4?? − 3?? + 7???? (a) Prove that this flow field is irrotational and that it satisfies the continuity equation. (b) Find the potential flow function Ф(??, ??) for this flow field with boundary condition Ф = 0 at x = 2, y = 1.
In: Mechanical Engineering
Why are the tolerance characteristics categorized as
forced
fitting and loose can't represent shape and position tolerance?
In: Mechanical Engineering
1. Control charts are usually expressed in terms of
average values and their dispersion.
Give an explanation (and the reason) about the condition of a
production system that is
stated in the control chart
2. From the results of the control chart analysis, how
to determine the correlation between
changes in product quality conditions for the causes?
In: Mechanical Engineering
2. Surface roughness of a machining product is an
important factor
determine the quality of geometry. Explain the following:
a. Explain how the surface roughness measurement tool works!
b. Explain the concept of measuring surface roughness!
c. How are the surface measurements results stated (written
down)?
In: Mechanical Engineering
In: Mechanical Engineering
At the beginning of compression of an ideal Diesel cycle the gas has a temperature and pressure of 400C and 90 kN/m2, respectively. The volume ratio of compression is 16:1. The maximum temperature of the cycle is 14000C. Determine, for the cycle,
Take, γ=1.4 , cp = 1.004 kJ/kg K.
In: Mechanical Engineering
One kilogram of air is taken through a constant volume cycle. At the commencement of the adiabatic compression, the pressure and temperature are 103 kN/m2 and 1000C respectively. The adiabatic compression has a volume ratio of 6:1. The maximum pressure of the cycle is 3.45 MN/m2. Determine, for the cycle,
For the air, take, R = 0.287 kJ/kg K, γ=1.4
In: Mechanical Engineering
A cooling plant adopted a two-stage cascade refrigeration system
to meet the required cooling load. In both upper and lower cycles,
the refrigerant leaves condenser as saturated liquid and enters
compressor as saturated vapor. The isentropic efficiency of the
upper cycle compressor is 80 %, while the lower cycle compressor is
70% efficient. The pressure limits of the upper and lower cycles
are 1 MPa and 0.2 MPa with refrigerant-134a, respectively. Heat
rejection from the lower cycle to the upper cycle takes place in an
adiabatic counterflow heat exchanger where the lower cycle enters
about at 0.5 MPa and the upper cycle enter about at 0.32MPa. If the
mass flow rate of the refrigerant in the upper cycle is 0.28 kg/s,
determine
i. the mass flow rate of the refrigerant in the lower cycle
ii. the rate of heat removal from the refrigerated space and the
power input into the compressors
iii. the COP of the refrigerator,
In: Mechanical Engineering
Evaluate the proportion of the heat of fuel carried away by the
flue gases for the following data: Coal with Calorific Value of 30
MJ/kg has composition by mass as follow: C= 78%, H=5%, 0,=8%, S=2%,
N2=2% and the remaining is ash. The coal is burnt in the
furnace with 50% excess air. The flue gases leaving the chimney at
327°C and the atmospheric temperature is at 15 °C. Assume perfect
combustion. Specific heat for dry product (Cp) is
1045J/kg. Heat is carried away per kilogram of moisture in the flue
gas is 3000kJ/kg. The composition of air by mass is as follow:
02 = 23% and N2= 77 %.
(20 marks, C5)
In: Mechanical Engineering
A cooling plant adopted a two-stage cascade refrigeration system to meet the required cooling load. In both upper and lower cycles, the refrigerant leaves condenser as saturated liquid and enters compressor as saturated vapor. The isentropic efficiency of the upper cycle compressor is 80 %, while the lower cycle compressor is 70% efficient. The pressure limits of the upper and lower cycles are 1 MPa and 0.2 MPa with refrigerant-134a, respectively. Heat rejection from the lower cycle to the upper cycle takes place in an adiabatic counterflow heat exchanger where the lower cycle enters about at 0.5 MPa and the upper cycle enter about at 0.32MPa. If the mass flow rate of the refrigerant in the upper cycle is 0.28 kg/s, determine
i. the mass flow rate of the refrigerant in the lower cycle
ii. the rate of heat removal from the refrigerated space and the power input into the compressors
iii. the COP of the refrigerator
In: Mechanical Engineering