Mechanical Engineering Answers

For the Scotch-yoke mechanism in the Figure below R = 203 mm, θ = 60°, and the crank

speed is 200 r/min. Find the velocity in meters per second and acceleration in meters per

second squared of the slider.

A disk 254 mm in diameter accelerates uniformly from a speed of 1000 r/min to 2000

r/min in 20 s. Find (a) the angular acceleration in radians per second squared and (b) the

revolutions of the disk during the 20-s interval.

An automobile accelerates from a speed of 32.2 km/h to 96.6 km/h in a distance of 89.3

m, which requires 5 s.

(a) If the acceleration is constant, find the acceleration in meters per second squared.

(b) Same as part (a) except the acceleration is not constant. What is the average

acceleration in meters per second squared?

Its shown in physics that the temperature ( ) , u x t at time t at the point x of a long,

insulated rod that lies along the x -axis satisfies the one-dimensional heat equation

2

2

u u

k

t x

 

=

 

, ( k is a constant).

Show that the function ( ) ( ) ( ) 2 u = u x, t = exp −n kt sin nx satisfies the one dimensional

heat equation for any choice of constant n

A wooden log of 0.8 m diameter and 6 m length is floating in a river water. Find the depth of wooden log in water when the sp. gr. Of the wooden log is 0.7.

In a triple riveted butt joint with two equal cover strips, having zigzag

arrangement of riveting the thickness of the plate 10 mm. Consider allowable

tensile, crushing and shear stress are 100 MPa, 150 MPa and 80 MPa

respectively. Calculate: - (i) diameter of rivet and (ii) pitch of rivet joint.

A simple flange coupling has to transmit 50 KW at 250 RPM. . Assume torque

to be 20 % more than the full load. Calculate (a) Shaft diameter (b) Key

Dimensions and (c) number & size of Bolts. The stresses are as under, For

Shaft & Key [σt] = 75 N/mm2, [] = 50 N/mm2,[σc] = 120 N/mm2 For Bolt

[]= 40 N/mm2

Air at a pressure of 101.3 k Pa and 288.8 K enters inside a tube having an inside diameter of 12.7 mm and a length of 1.52 m with a velocity of 24.4 m/s. Condensing steam on the outside of the tube maintains the inside wall temperature at 372.1 K . Calculate the convection coefficient of the air. ( Note: This solution is trial and error. First, assume an outlet temperature of the air. )

Determine The Saturated Temperature, Saturated Pressure And Enthalpy For Water At Specific Volume Of Saturated Vapor At 10.02 m^3/kg.

A piston-cylinder device contains 0.1 m3 of liquid water and 0.9 m3 of water vapor in equilib­rium at 800 kPa. Heat is transferred at constant pressure until the temperature reaches 350°C.

(a) What is the initial temperature of the water?

(b) Determine the total mass of the water.

(c) Calculate the final volume.

(d) Show the process on a P-v diagram with respect to saturation lines.