A rigid body is in a stable equilibrium if the application of any force
Can raise the CG of the body but cannot lower it
Tends to lower the CG of the body
Neither raises nor lowers the CG of the body
None of above
Correct Answer :
A. Can raise the CG of the body but cannot lower it
Related Questions
Which of the following is a scalar quantity?
Energy
Momentum
Torque
Impulse
If the horizontal range is 2.5 times the greatest height, the angle of projection of the projectile, is
57°
58°
59°
60°
On a ladder resisting on a smooth ground and leaning against a rough vertical wall, the force of friction acts
Towards the wall at its upper end
Away from the wall at its upper end
Upwards at its upper end
Downwards at its upper end
According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centres lie on
A point
A straight line
Two straight lines
A triangle
The load shared by the member BC of the structure shown in below figure is
23 t
32 t
4 t
3 t
The force polygon representing a set of forces in equilibrium is a
Triangle
Open polygon
Closed polygon
Parallelogram
The C.G. of the shaded area of the below figure whose curve OM is a parabola from y-axis, is 
a/4
3a/4
3b/10
3a/10
The resultant of the forces acting on a body will be zero if the body
Rotates
Moves with variable velocity in a straight line
Moves along a curved path
Does not move at all
One end of an elastic string of natural length / and modulus X is kept fixed while to the other end is attached a particle of mass m which is hanging freely under gravity. The particle is pulled down vertically through a distance x, held at rest and then released. The motion is
A simple harmonic motion
A rectilinear motion with constant speed
A damped oscillatory motion
None of the above
For lifting a load of 50 kg through a distance of 2.5 cm, an effort of 12.5 kg is moved through a distance of 40 cm. The efficiency of the lifting machine, is
60 %
65 %
70 %
75 %
The tension in a cable supporting a lift
Is more when the lift is moving downwards
Is less when the lift is moving upwards
Remains constant whether its moves downwards or upwards
Is less when the lift is moving downwards
Two balls of masses 3 kg and 6 kg are moving with velocities of 4 m/sec and 1 m/sec respectively, towards each other along the line of their centers. After impact the 3 kg ball comes to rest. This can happen only if the coefficient of restitution between the balls is
2/3
1/5
3/5
1/3
Pick up the correct statement from the following. The kinetic energy of a body
Before impact is equal to that after impact
Before impact is less than that after impact
Before impact is more than that after impact
Remain constant
Pick up the correct statement from the following for the structure shown in below figure.
The horizontal reaction at A is 2 √3t ←
The horizontal reaction at C is 2 √3t →
The vertical reaction at A is zero
All the above
The apparent weight of a man in a moving lift is less than his real weight when it is going down with
Uniform speed
An acceleration
Linear momentum
Retardation
It is observed that in a certain sinusoidal oscillation, the amplitude is linearly dependent on the frequency f. If the maximum velocity during the oscillation is V, then V must be proportional to
f
1/f
1/f²
f²
A heavy ladder resting on a floor and against a vertical wall may not be in equilibrium, if
Floor is smooth and the wall is rough
Floor is rough and the wall is smooth
Floor and wall both are smooth surfaces
Floor and wall both are rough surfaces
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
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 the angle between the applied force and the direction of motion of a body, is between 90° and 180°, the work done, is called
Virtual work
Imaginary work
Zero work
Negative work
A rigid body suspended vertically at a point and oscillating with a small amplitude under the action of the force of gravity, is called
Simple pendulum
Compound pendulum
Second's pendulum
None of these
The force acting on a point on the surface of a rigid body may be considered to act
At the centre of gravity of the body
On the periphery of the body
On any point on the line of action of the force
At any point on the surface normal to the line of action of the force
If two forces of 3 kg and 4 kg act at right angles to each other, their resultant force will be equal to
7 kg
1 kg
5 kg
None of these
Time required to stop a car moving with a velocity 20 m/sec within a distance of 40 m, is
2 sec
3 sec
4 sec
5 sec
A uniform pyramid and a uniform prism of same height lie with their base on the surface. Which is more stable?
Pyramid
Prism
Both equally stable
None of the above
If a ball which is dropped from a height of 2.25 m on a smooth floor attains the height of bounce equal to 1.00 m, the coefficient of the restitution between the ball and floor, is
0.25
0.50
0.67
0.33
A body is dropped from a height of 100 m and at the same time another body is projected vertically upward with a velocity of 10 m/sec. The two particles will
Never meet
Meet after 1 sec
Meet after 5 sec
Meet after 10 sec
If the radius of the earth is 600 km the height of a mountain above sea level at the top of which a beat seconds pendulum at sea level, looses 27 seconds a day, is
500 metres
1000 metres
1500 metres
2000 metres
The numbers of funicular polygons which can be drawn to pass through two specified points in the space diagram are
Zero
1
2
Infinity
The motion of a particle moving with S.H.M. from an extremity to the other, constitutes
Half an oscillation
One full oscillation
Two oscillations
None of these