Mechanical Engineering Answers

. Two bodies A and B in figure are separated by a spring. Their motion down the incline is resisted by a force P = 800 N . The coefficient of kinetic friction is 0.30 under A and 0.10 under under B. a.) compute the acceleration of block A b.) Compute the acceleration of block B c.) Determine the force in the spring.

Air flows steadily at the rate of 0.4 kg/s through an air compressor,

entering at 6 m/s with a pressure of 1 bar and a specific volume of

0.85 m3/kg, and leaving at 4.5 m/s with a pressure of 6.9 bar and a

specific volume of 0.16 m3/kg. The internal energy of air leaving is 88

kJ/kg greater than that of the air entering. Cooling water in a jacket

surrounding the cylinder absorbs heat from the air at the rate of 59

kJ/s. Calculate the power required to drive the compressor and the

inlet and outlet pipe cross-sectional areas.

A turbine operating under steady flow conditions receives steam at the

following state : pressure 13.8 bar ; specific volume 0.143 m3/kg ;

internal energy 2590 kJ/kg ; velocity 30 m/s. The state of the steam

leaving the turbine is : pressure 0.35 bar ; specific volume 4.37 m3/kg

; internal energy 2360

kJ/kg ; velocity 90 m/s. Heat is lost to the surroundings at the rate of

0.25 kJ/s. If the rate of steam flow is 0.38 kg/s, what is the power

developed by the turbine ?

15 kg of air per minute is delivered by a centrifugal compressor. The

inlet and outlet conditions of air are :

C1 = 10 m/s, p1 = 1 bar, v1 = 0.5 m3/kg and C2 = 80 m/s, p2 = 7 bar,

v2 = 0.15 m3/kg. The increase in enthalpy of air passing through the

compressor is 160 kJ/kg, and heat loss to the surroundings is 720

kJ/min.

Assuming that inlet and discharge lines are at the same level, find :

(i) Motor power required to drive the compressor.

(ii) Ratio of inlet to outlet pipe diameter.

Explain the Principles of sustainable design. [

Slider crank mechanism as shown in the figure calculate the i) Acceleration of the slider B ii) Acceleration of the point E iii) Angular acceleration of the link AB OA rotates at (30+X) rad/s in counter clockwise direction (10marks) X is the last digit of the student roll no. for example if the student roll no is A09 then X=9 and ω=30+9=39 rad/s. Draw the neat and clean diagram with proper scale. Rough drawings will not be considered

In a slider crank mechanism the length of the crank OB is (100+X)mm and length of the connecting rod is (475+X)mm. The center of gravity G of the connecting rod is (250+X)mm from the slider A. crank speed is (500+X)rpm clockwise. When the crank has turned 45 deg. From the inner dead center. Determine( using both relative velocity method and Instantaneous center method) 1. Velocity of the slider 2. Velocity of point G 3. Angular velocity of the connecting rod AB Note where X is two digit number made from the last two digit of the registration number of the students For example if the reg. no. of the student is 11912081 then X=81 Draw the neat and clean diagram with proper scale. Rough drawings will not be considered 

In crank and slotted lever quick return mechanism, the crank length is (100 +X )mm and the distance between the fixed center is (225+X)mm. The length of the slotted lever is (525+X)mm. Determine the ration of time of cutting stroke to time of return stroke. Also calculate the length of the stroke . Note where X is two digit number made from the last two digit of the registration number of the students For example if the reg. no. of the student is 11912081 then X=81 and crank length is 80+81=161mm Draw the neat and clean diagram with proper scale. Rough drawings will not be considered. 

Consider an ordinary shower where hot water at 60°C is mixed with cold water at 10°C. If it is desired that a steady stream of warm water at 45°C be supplied, determine the ratio of the mass flow rates of the hot to cold water. Assume the heat losses from the mixing chamber to be negligible and the mixing to take place at a pressure of 150 kPa. 

A water heater shower needs to supply warm water at temperature of 40°C. The hot water input is at 90°C and flowing with a flow rate of 0.5 kg/s at one side. On the other side, a stream of cold water flowing at 25°C. If we need the shower to supply water at 40°C at the exit, calculate the mass flow rate that is suitable for the cold water side. Assume all stream at equal pressure of 250 kPa.