Mechanical Engineering Answers

A multiple disc clutch has three discs on the driving shaft and two on the driven shaft, providing four pairs of contact surfaces. The outer diameter of the contact surfaces is 250 mm and the inner diameter is 150 mm. Determine the maximum axial intensity of pressure between the discs for transmitting 18.75 kW at 500 r.p.m. Assume uniform wear and coefficient of friction as 0.3 solution

A particle has such a curvilinear motion that its x coordinate is defined by 𝑥 = 5𝑡 3 −105𝑡 where 𝑥 is in inches and 𝑡 is in seconds. When 𝑡 = 2 𝑠, the total acceleration is 75 𝑖𝑛/𝑠 2 . If the y component of acceleration is constant and the particle starts from rest at the origin when 𝑡 = 0, determine its total velocity when 𝑡 = 4 𝑠.

Answer: 𝒗 = 𝟏𝟖. 𝟕𝟓 𝒇𝒕/s

A particle has such a curvilinear motion that its x coordinate is defined by 𝑥 = 5𝑡 3 −105𝑡 where 𝑥 is in inches and 𝑡 is in seconds. When 𝑡 = 2 𝑠, the total acceleration is 75 𝑖𝑛/𝑠 2 . If the y component of acceleration is constant and the particle starts from rest at the origin when 𝑡 = 0, determine its total velocity when 𝑡 = 4 𝑠.

Answer: 𝒗 = 𝟏𝟖. 𝟕𝟓 𝒇𝒕/s

A small 250g collar C can slide on a semicircular rod which is made to rotate about the vertical AB at a constant rate of 7.5rad/s. Determine the 3 values of theta for which the collar will not slide on the rod, assuming no friction b/w the collar and the rod.

Compute for the total volume concrete needed for the concreting of columns, assume that the height of the column starting at NGL is 15.00 meters. 

• A firm uses simple exponential smoothing with α = 0.3 to demand forecast. The forecast for the first week of January was 500 units, whereas actual demand turned out to be 450 units.
• a. Forecast the demand for the second week of January.
• b. Assume that the actual demand during the second week of January turned out to be 550 units. Forecast the demand up to February third week, assuming the subsequent demands as 475, 450, 470, 525 and 470 units.

A Refrigerator produces a refrigerating effect ( i.e heat removed ) of 8.5MJ/min. If the 

COP of the refrigeration system is 3. Determine the power required to run the compressor.

An object with mass

m

= 0.6 kg is dropped from the top of a building and falls 21 m down in the ground

1.1 Calculate the speed of the object as it hits the ground and calculate

the time for the fall.

Neglect

in this question

the air resistance.

In a more accurate calculation we need to take air resistance into account.

In a wind tunnel the air resistance of the object has been measured giving

rise to an acceleration of:

air = 0.03v^2

where v is the speed of the object.

1.2 Now, taking air resistance into account, find the speed of the object as it

hits the ground. Any integrals in your calculation should be calculated

by hand!

1.3 Calculate the time of the fall when air resistance is taken into account.

In a Stirling cycle with an ideal regenerator, the volume varies between 0.03 and 0.06 m³, the maximum pressure is 2 atmosphere, and the temperature varies between 500°C and 250°C. The working fluid is air. Compute the network and the cycle thermal efficiency.

0.98 lb_m/s of Nitrogen initially at 390 psia, 9 ft³/min, 299°F are cooled isometricall to 118°F in an internally reversible manner. Compute P₂, ⌠pdv, -⌠vdp, ▲U, ▲H, Q and ▲S for a nonflow process. (This is the exact question in the book Sir/Ma'am)