Mechanical Engineering Answers

a lump of steel of mass 8 kg at 1000 k is dropped in 80 kg of oil at 300 k. calculate the entropy change of steel the oil and the universe. take specific heats of steel and oil as 0.5 kj/kg K and 3.5 Kj /kg K respectively.

The motion of a cylinder of radius r is controlled by a cable AG. Knowing that end G of the cable has a

velocity of VG = 0.3 m/s and an acceleration of aG, = 0.5 m/s' , both directed upward, and that r = 0.15 m

determine the acceleration (a) of point B and of point D, (b) the velocity and acceleration of point E.

For the hydraulic motor shown below, the pump pulls linseed oil from tank A via a 3 ½”

Sch40 steel pipe at a flow rate of 620 L/min. The pump is rated at 30hp and has an efficiency of 80%. If the pipe from the pump outlet to the hydraulic motor is 2” Sch40 steel pipe and the pipe from the motor outlet back to tank A is 3 ½” Sch40 steel pipe and the following data are known:

1.Energy loss from tank A to the pump inlet is 6.2 Nm/N.

2.Energy loss from pump outlet to inlet to hydraulic motor is 1.2 Nm/N.

3.Energy loss from outlet of hydraulic motor to tank A inlet is 2.5 Nm/N.

Ignoring all other losses, compute the following:

1. Pressure at the pump inlet.

2. Pressure at the pump outlet.

3.Pressure at the hydraulic motor inlet.

4.Pressure at the hydraulic motor outlet.

5.Power removed from the fluid by the hydraulic motor

3.2. Nitrogen (molar mass 28 kg/kimol) expands reversibly in a perfectly thermally (insulated) cylinder from 3.5 bar, 200°C to a volume of 0,09 m°. The initial volume occupied was 0.03 m". Assume nitrogen to be a perfect gas and take Cy = 0.741 kJ/kg K. Calculate the work done.

What makes axial flow fans more suitable for applications where large flow rates of air are to be handled. What new developments have taken place in the design of fans for air conditioning applications?

determine the saturated temperature, saturated pressure and enthalpy for water at specific volume of saturated vapor at 10.02 m³/kg

Two kg of air in a closed system undergoes an isothermal process from 606 kPa and 200°C to 75 kPa. The heat transfer (expressed to ZERO decimal places) during the process is in kJ:

From the tables (air is assumed as ideal gas based on given conditions), the gas constant for air:  R = 0.2870 kJ/kg·K.

Design a spring for suspension system of a motorcycle with a weight of two people riding the bike. You should assume the required parameters as per the following table,

Sr. No.

Reg No

Starting d

Difference for selection of diameter

Ends of spring

1

1-10

0.01 x R

0.001 x R

Squared or Closed

2

11-20

0.01 x R

0.001 x R

Squared or Closed

3

21-30

(0.01 x R)/2

0.001 x R

Squared and Ground

4

31-40

(0.01 x R)/2

0.001 x R

Squared and Ground

5

41-50

0.01 x R

0.001 x R

Squared or Closed

6

51-60

0.01 x R

0.001 x R

Squared or Closed

7

61-70

(0.001 x R)/2

0.001 x R

Squared and Ground

8

71-80

(0.001 x R)/2

0.001 x R

Squared and Ground

* where R = Your Registration Number

Start your calculation first by using material 302 stainless steel and if the required result is not output, then change the material till you find one. Select the spring as wound.

HINT: Make an excel sheet for making the table of spring selection.

A rope AB, 2.7 m long is connected at A and B to two points on the same level, 2.4 m apart. A load of 136 N is suspended from a point C on the rope 90 cm from A. What load connected to a point D on the rope, 60 cm from B, will be necessary to keep the portion CD level?

An air standard ideal Diesel engine (k for air = 1.4) operates with a pressure and temperature at the start of the compression stroke of 14.7 psia and 550°R. If the cut-off ratio and clearance volume are 2.5 and 1.0 ft3, respectively, calculate

(a) Pressure, temperature and specific volume at the 4 states of the cycle

(b) Clearance

(c) Thermal efficiency

(d) MEP for the cycle.