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F1040 Pages: 4

direction when viewed from the front, and is equivalent to a mass of 75 kg
having a radius of gyration of 100 mm. If the car is taking a right turn of 60 m
radius at 60 km/h, find the load on each wheel.
PART ட
Answer any four full questions, each carries 10 marks.
What is damping factor?

In a single degree damped vibration system, a suspended mass of 8 Kg
makes 30 oscillation in 18 second. The amplitude decreases to 0.25 of the
initial value after 5 oscillations. Determine 1. The stiffness of the spring, 2.
Logarithmic decrement, 3. Damping factor and 4. Damping coefficient

The mass of an electric motor is 120 kg and it runs at 1500 r.p.m. The armature
mass is 35 kg and its C.G. lies 0.5 mm from the axis of rotation. The motor is
mounted on four springs of negligible damping so that the force transmitted is
one-eleventh of the impressed force. Assume that the mass of the motor is
equally distributed among the four springs. Determine: 1. stiffness of each
spring; 2. dynamic force transmitted to the base at the operating speed and 3.
natural frequency of the system.

Explain the term ‘dynamic magnifier’. What do you understand by
transmissibility?

A beam of length 10 m carries two loads of mass 200 kg at distances of 3 m from
each end together with a central load of mass 1000 kg. Calculate the frequency of

transverse vibrations. Neglect the mass of the beam and take I = 109 നന്‌ and

E = 205x103 N/mm’.

A steel shaft ABCD 1.5 m long has flywheel at its end A and D. The mass of the
flywheel A is 600 Kg and has a radius of gyration of 0.6 m. The mass of the
flywheel D is 800 Kg and has a radius of gyration of 0.9 m. The connecting shaft
has a diameter of 50 mm for the portion AB which is 0.4 m long; and has a
diameter of 60 mm for the portion BC which is 0.5 m long ; and has a diameter
of ‘d’ mm for the portion CD which is 0.6 m long. Modulus of rigidity for the
shaft material is 80GN/m? Determine

1. The diameter ‘d’ of the portion CD so that the node of the torsional

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