The C.G. of a thin hollow cone of height h, above its base lies on the axis, at a height of
h/3
h/4
2h/3
3h/4
Correct Answer :
C. 2h/3
Related Questions
The necessary condition of equilibrium of a body is:
Algebraic sum of horizontal components of all the forces must be zero
Algebraic sum of vertical components of all the forces must be zero
Algebraic sum of the moments of the forces about a point must be zero
All (a), (b) and (c)
The units of inertia of mass are
kg/m
kg/m2
m4
kg-m2
The ends of a string weighing w/metre are attached to two points at the same horizontal level. If the central dip is very small, the horizontal tension of the string throughout is
wl/4d
wl²/4d
wl²/8d
wl²/16d
If a spherical body is symmetrical about its perpendicular axes, the moment of inertia of the body about an axis passing through its centre of gravity as given by Routh's rule is obtained by dividing the product of the mass and the sum of the squares of two semi-axes by n. Where, n is
2
3
4
5
The load shared by the member BC of the structure shown in below figure is
23 t
32 t
4 t
3 t
One Newton is equivalent to
105 dyne
106 dyne
107 dyne
108 dyne
Two forces act an angle of 120°. If the greater force is 50 kg and their resultant is perpendicular to the smaller force, the smaller force is
20 kg
25 kg
30 kg
35 kg
The characteristic of a couple is:
Algebraic sum of forces, constituting a couple is zero
Algebraic sum of moments of forces, constituting a couple, about any point, is same
A couple can be never the balanced by a single force
All the above
The ratio of the reactions RA and RB of a simply supported beam shown in below figure is 
0.50
0.40
0.67
1.00
Two loads of 50 kg and 75 kg are hung at the ends of a rope passing over a smooth pulley shown in below figure. The tension in the string is: 
50 kg
75 kg
25 kg
60 kg
A projectile is fired at an angle θ to the vertical. Its horizontal range will be maximum when θ is
0°
30°
45°
90°
The moment of inertia of a hollow circular section whose external diameter is 8 cm and internal diameter is 6 cm, about centroidal axis, is
437.5 cm4
337.5 cm4
237.5 cm4
137.5 cm4
For a given velocity of a projectile, the range is maximum when the angle of projection is
30°
45°
90°
0°
A hoop of radius 3 m weighs 100 kg. It rolls along a horizontal floor so that at its centre of mass has a speed of 200 mm/sec. The work required to stop the hoop is
2 J
4 J
6 J
8 J
If the kinetic energy and potential energy of a simple harmonic oscillator of amplitude A are both equal to half the total energy, then the displacement is equal to
A
A/2
A/√2
A√2
The resultant of two forces P and Q is R. If Q is doubled, the new resultant is perpendicular to P. Then,
P = R
Q = R
P = Q
None of the above is correct
The piston of a steam engine moves with a simple harmonic motion. The crank rotates 120 r.p.m. and the stroke length is 2 metres. The linear velocity of the piston when it is at a distance of 0.5 metre from the centre, is
5.88 m/sec
8.88 m/sec
10.88 m/sec
12.88 m/sec
The intrinsic equation of catenary is
S = c tan ψ
y = c cosh x/c
y = c cosh ψ
y = c sinh ψ
A smooth cylinder lying on its convex surface remains
In stable equilibrium
In unstable equilibrium
In neutral equilibrium
Out of equilibrium
If A is the amplitude of particle executing simple harmonic motion, then the total energy E of the particle is
Proportional to A
Proportional to A²
Proportional to 1/A²
Independent of A
A stone is thrown vertically upwards with a vertical velocity of 49 m/sec. It returns to the ground in
5 sec
8 sec
10 sec
20 sec
The horizontal reaction at the support A of the structure shown in below figure, is
Zero
2 t
3 t
1 t
If l is the span of a light suspension bridge whos each cable carries total weight (w) and the central dip is y, the horizontal pull at each support, is
wl/4y
wl/8y
wl/2y
wl
A ladder of weight 'w' rests against a smooth vertical wall, and rests on rough horizontal ground, the coefficient of friction between the ladder and the ground being 1/4. The maximum angle of inclination of the ladder to the vertical, if a man of weight 'w' is to walk to the top of it safely, is tan'1 x, where x is
1/4
1/3
3
4
The member forces in a statically in determinate truss
Can be obtained by graphic statics
Cannot be obtained by graphic statics
May be obtained by graphic statics
Can be obtained by graphic statics by trial and error
If the horizontal range is 2.5 times the greatest height, the angle of projection of the projectile, is
57°
58°
59°
60°
The maximum pull in a cable, carrying a uniformly distributed load and supported at two ends which are at the same level, is at
Supports
Quarter span
Mid span
None of the above
In simple harmonic motion, acceleration of a particle is proportional to
Rate of change of velocity
Displacement
Velocity
Direction
A weight W is suspended at the free end of a light member hinged to a vertical wall. If the angle of inclination of the member with the upper wall is θ°, the force introduced in the member, is
W sec θ
W cos θ
W sin θ
W cosec θ
If the direction of projection bisects the angle between the vertical and the inclined plane, then the range of projectile on the inclined plane is
Zero
Maximum
Minimum
None of these