Mechanical Engineering Answers

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A 1.5m long column has a circular cross section of 5 cm in diameter. One of the ends of the columns is fixed in direction and position and the other end is free. Given that the factor is safety is 3. Calculate the safe load through the use of

(i) Rankine's formula, take that the yield stress as 560 N/mm² and α = 1/600 for pinned ends

A rigid flange coupling is used to connect a 45KW 1440rpm electric motor to a centrifugal pump. The starting torque of the motor is 225% of the rated torque. There are 8 bolts and their pitch circle diameter is 150mm . The bolts are made of steel 45C8 (sigma yt 380N/mm2 ) the factor of safety is 2.5 . Determine the diameter of the bolts. Assume (sigma sy 0.577 sigma yt) . Assume that the bolts are finger tight is reamed and ground holes.

A wedge belt is required to transmit 18.5kw from an electric motor running at 1455rpm to a uniformly loaded conveyor running at 400rpm. The desired center distance is 1.4m select a suitable belt and determine the diameter of the pulleys

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.