95AM-4
Sr. No. 10
EXAMINATION OF MARINE ENGINEER OFFICER
Function: Marine Engineering at Operational Level
APPLIED MECHANICS
M.E.O. Class IV
(Time allowed - 3hours)
Morning Paper
India (2003)
Total Marks 100
NB : (1) All Questions are Compulsary
(2) All Questions carry equal marks
(3) Neatness in handwriting and clarity in expression carries weightage
(4) Illustration of an Answer with clear sketches / diagrams carries weightage.
1.
A vertical sluice gate 1.8 m square covers an outlet to the sea. The gate is hinged along its top edge
and opens into the sea. When the level of sea water is 0.9 m above the hinge and dry on the other
side of the gate, calculate (i) the total water thrust on the gate, (ii) the horizontal force to apply at the
bottom edge to open the gate. Take the density of sea water as 1.024 g/ml.
2.
Freshwater issues from a hole 16 mm diameter in the side of a tank, the head of water above the
hole being 2.14 m. Taking the coeflicient of area as 0.64 and the coefficient of velocity as 0.97,
calculate the litres of water passing through the hole every minute.
3.
TWO spur wheels in gear transmit a power of 6.7 kW. The driver has 40 teeth of 12 mm pitch and
runs at 7 rev/s, find the force on the teeth. If the driven wheel has 240 teeth find the ratio of the
torque in the two shafts.
4.
50 kN
Above is a sketch of a roof structure, the lower inclined members are at a degree of 15 degrees to the
horizontal and the upper inclined members are at 45 degrees. It is simply supported at each end and the
structure carries a load of 50 kN on the apex. Construct the vector diagram for the whole structure,
measure off the force in each member and state whether they are in compression or tension.
5.
A body of 40 N weight is to be pulled along a horizontal plane, the coefficient of friction between
the body and the plane being 0.3. If the line of action of the applied force is inclined upwards at 26
degrees to the horizontal, find the magnitude of the force to slide the body at steady speed. Find
also the magnitude and direction of the least force that will move the body.
6.
A forging requires a force of 36 kN to pull it up a ramp, and 2 kN to pull it down, the coefficient
of friction between forging and the ramp being 0.4. Calculate the angle of the ramp inclined to the
horizontal and the weight of the forging in kilonewtons.
7.
There are four pulleys in each block of a set of rope pulley blocks. If the efficiency is 70% when
lifting a load of 2.8 kN, what is the effort applied? What is the efficiency of each pulley ?
8.
Find the minimum thickness of a solid drawn steel pipe 230 mm internal diameter if the stress in
the material is not to exceed 24 MN/m2 when the internal fluid pressure is 20 bar.
(=20 X 105 n/m2 )
9.
A mass of 544 kg is lifted out of a hold by a wire rope from a winch drum of 380 mm effective
diameter. If the mechanical efficiency is 70%, find the power of the driving motor when the
winding drum is rotating at a steady speed of 40 rev/min.
10.
A hole is bored in a circular disc of uniform thickness. The centre of the hole is 38 mm from the
centre of the disc and the mass of material removed is 0.8 kg. Calculate the centrifugal force set
up when the bored disc rotates about its geometrical centre at 240 rev/min.
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