Mechanical Engineering Answers

Air flows steadily through an engine at a constant temperature of 400k. Find the work per kilogram if the exit pressure is one-third the inlet pressure and the inlet pressure is 207 KPa. Assume that the kinetic energy and potential energy variation is negligible.

A steel wire ABC 16 m long having cross sectional area of 4 mm2 weighs 20 N as shown in figure 1.1. If the modulus of elasticity for the wire material is 200 GPa, find the deflections at points C ad D.

(a) The pitch circle diameter of the smaller of the two spur wheels which mesh externally an lute teeth is 100 mm. The number of teeth are 16 and 32. The pressure angle is 20 degrees a endum is 0.32 of the circular pitch. Find the length of the path of contact of the pair of teeth.

A pair of gears, having 40 and 30 teeth respectively are of 25° involute form. The addendum le m and the module pitch is 2.5 mm. If the smaller wheel is the driver and rotates at 1500 r.p.n velocity of sliding at the point of engagement and at the point of disengagement.

Find the cumulative distribution function of the random variable X  representing the number of defective in problem a. Then using F(x). Find

        P(X=1) and P (0<X£2)

Sketch the Constant pressure cycle (Brayton Cycle) on clear p-v and T-s diagram. And explain all the four processes. 

Problem 1 Stone A is hurled vertically upwards from a tower of height h with a speed vA0. Simultaneously, stone B is thrown vertically upwards from the ground with a speed of vB0. Given: h = 30 m ; vA0 = 15 m/s ; vB0 = 25 m/s ; g = 9.81 m/s 2 Find: 1. At which height and time do the stones fly past another? 2. At this time, what is the speed of stone A relative to stone B? 3. Draw the following diagrams: acceleration-time, speed-time and distance-time.Problem 2 In the system pictured below, point B slides with velocity vሬ⃗஻. Given: β, , vሬ⃗஻ Find: The velocity vሬ⃗஼ of point C by calculation

1, In a hydroelectric power plant, water enters the turbine nozzles at 800 kPa absolute with a low velocity. If the nozzle outlets are exposed to atmospheric pressure of 100 kPa, determine the maximum velocity to which water can be accelerated by the nozzles before striking the turbine blades.

2, An airplane is flying at an altitude of 12,000 m. Determine the gage pressure at the stagnation point on the nose of the plane if the speed of the plane is 300 km/h.

1. A 0.75-m^3 rigid tank initially contains air whose density is 1.18 kg/m^3. The tank is connected to a high- pressure supply line through a valve. The valve is opened, and air is allowed to enter the tank until the density in the tank rises to 4.95 kg/m^3. Determine the mass of air that has entered the tank.

2. A desktop computer is to be cooled by a fan whose flow rate is 0.40 m^3/min. Determine the mass flow rate of air through the fan at an elevation of 3400 m where the air density is 0.7 kg/m^3. Also, if the average velocity of air is not to exceed 110 m/min, determine the minimum diameter of the casing of the fan.

A shipment of 7 television sets contains 2 defective sets A hotel makes a random purchase of 3 of the sets: a) If x is the number of defective sets purchased by the hotel, find the probability distribution of x Express the results graphically as a probability histogram. b) Find the cumulative distribution function of the random variable X representing the number of defectives. Then using flx), find (a) p(X = 1); (b) p(O < X s 2).

Using the method of joints, calculate the force in each member of the trusses shown. State whether each member is in tension or compression. Note that the truss geometry is symmetric. E 8 ft A B D IC QIQI 6 ft 8 ft 2000 lb -6ft- 1200 lb