7/27/2019 ASSIGNMENT 2 final.docx

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Assignment

No.ASSIGNMENT DURATION SUBJECT

SUBMISSION

DATE

by Student

CHECKED BY FACU

REPORT TO

COORDINATO

2 30/8/2013 to 6/9/2013

Mechanical

Vibration7thsemester

9/9/2013 13/9/2013

Objective Types Questions (GATE PSU & IES)

1.) When there is a reduction in amplitude over every cycle of vibration, then the body

is said to have

(a) Free vibration (b) forced vibration

(c) damped vibration (d) transient vibration.

2.)Longitudinal vibrations are said to occur when the particles of a body moves(a)perpendicular to its axis (b) parallel to its axis

(c)in a circle about its axis (d) in a Parabola about its axis.

3. When a body is subjected to transverse vibrations, the stress induced in a body will

be(a)shear stress (b) tensile stress

(c) compressive stress (d) compressive and tensile both stress.

4. The factor which affects the critical speed of a shaft is(a) Diameter of the disc (b) span of the shaft

(c) eccentricity (d)all of these.

5. If the roots of this equation are real, then the system will be(a) over damped (b) under damped

(c) critically damped (d)none of these.

Long Answer Types Questions

1. Derive the equation of motion for free vibration of undamped SDOF systems usingNewtons methods and energy method.

2. What is meant by vibrations? Define free and Force vibration.3. What is the difference between harmonic motion and periodic motion? A given Harmonic

motion 10sin t. Show the relative position and magnitude of displacement , velocity and

acceleration vector at time t=0, for the case when

(a)= 2.0 rad/sec(b)= 0.5 rad/sec

4. A simple pendulum of length 5 m, with a bob ofmass 1 kg, is in simple harmonic motion as it

passes through its mean position, the bob has aspeed of 5 m/s. What is the net force on the bob at

the mean position.

5. A mass of 1 kg is suspended by means of 3 springsas shown in figure. The spring constants K1, K2

and K3 are respectively 1 kN/m, 3kN/m and 2

kN/m. find out the natural frequency of the system.

7/27/2019 ASSIGNMENT 2 final.docx

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6. An air-conditioning chiller unit weighing 2,000 Kg is to be supported by four air springs.Design the air springs such that the natural frequency of vibration of the unit lies between5 rad/s and 10 rad/s.

7. Find out the natural frequency and equation of motions for the following system using theenergy conservation method.

8. Find out the natural frequency and equation of motions for the following system using theenergy conservation method.

9. A U-tube manometer used for measuring the gas or liquid pressure. The cross sectionalarea is A. length is l and density of liquid or gas is obtain the deferential equation of

motion for U-tube manometer b) period of oscillation.

10.What is meant by logarithmic decrement? Derive the equation for logarithmicdecrement?