The maximum frictional force which comes into play, when a body just begins to slide over the surface of a another body, is known
Sliding friction
Rolling friction
Limiting friction
None of these
Correct Answer :
C. Limiting friction
Related Questions
The centre of gravity of the trapezium as shown in below figure from the side is at a distance of
(h/3) × [(b + 2a)/(b + a)]
(h/3) × [(2b + a)/(b + a)]
(h/2) × [(b + 2a)/(b + a)]
(h/2) × [(2b + a)/(b + a)]
A particle moves with a velocity of 2 m/sec in a straight line with a negative acceleration of 0.1 m/sec2. Time required to traverse a distance of 1.5 m, is
40 sec
30 sec
20 sec
15 sec
On a ladder resting on a rough ground and leaning against a smooth vertical wall, the force of friction acts
Downwards at its upper end
Upwards at its upper end
Perpendicular to the wall at its upper end
Zero at its upper end
If a projectile is fired with an initial velocity of 10 m/sec at an angle of 60° to the horizontal, its horizontal and vertical velocity at the highest point of trajectory are
0 and 5 m/sec
5 m/sec and 0
5√3 m/sec and 0
5 and 5√3 m/sec
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
A vehicle weighing w kg is to run on a circular curve of radius r. If the height of its centre of gravity above the road level is h and the distance between the centres of wheels is 2a, the maximum velocity, in order to avoid over turning, will be
gra/h
√(gra/h)
3√(gra/h)
4√(gra/h)
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
If the given forces P₁, P₂, P₃ and P₄ are such that the force polygon does not close, then the system will
Be in equilibrium
Always reduce to a resultant force
Always reduce to a couple
Both (A) and (C)
Cartesian form of the equation of catenary is
y = c cosh x/c
y = c sinh x/c
y = c tan x/c
y = c sin x/c
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
When a body moves round a fixed axis, it has
A rotary motion
A circular motion
A translatory
A rotary motion and translatory motion
A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec²)
15 m/sec
25 m/sec
40 m/sec
50 m/sec
The total kinetic energy of a hoop of mass 2 kg and radius 4 m sliding with linear velocity 8 m/sec and angular velocity 5 radian/sec is
64 J
400 J
464 J
89 J
A projectile has maximum range of 40 m on a horizontal plane. If angle of projection is a and the time of flight is 1 second, then sin a must be about (Assume g = 10 m/sec²)
1/4
1/3
1/2
1/5
The force polygon representing a set of forces in equilibrium is a
Triangle
Open polygon
Closed polygon
Parallelogram
If the tension in a cable supporting a lift moving upwards is twice the tension when the lift is moving downwards, the acceleration of the lift, is
g/2
g/3
g/4
g/5
A square hole is made in a circular lamina, the diagonal of the square is equal to the radius of the circle as shown in below figure the shift in the centre of gravity is 
r (π - 0.75)/(π - 0.5)
r (π - 0.25)/(π - 0.75)
r (π - 0.5)/(π - 0.75)
r (π - 0.5)/(π - 0.25)
Pick up the incorrect statement from the following:
The C.G. of a circle is at its centre
The C.G. of a triangle is at the intersection of its medians
The C.G. of a rectangle is at the intersection of its diagonals
The C.G. of a semicircle is at a distance of r/2 from the centre
In a simple harmonic motion, the position of equilibrium is always
Stable
Unstable
Neutral
None of the above
Periodic time of body moving with simple harmonic motion, is
Directly proportional to its angular velocity
Directly proportional to the square of its angular velocity
Inversely proportional to the square of its angular velocity
Inversely proportional to its angular velocity
The following factor affects the orbit of a satellite up to an altitude of 720 km from the earth's surface
Uneven distribution of the gravitational field
Gravity of the sun and the moon
Aerodynamic forces
None of these
A 49 kg lady stands on a spring scale in an elevator. During the first 5 sec, starting from rest, the scale reads 69 kg. The velocity of the elevator will be
10 m/sec
15 m/sec
20 m/sec
25 m/sec
A smooth cylinder lying on its convex surface remains
In stable equilibrium
In unstable equilibrium
In neutral equilibrium
Out of equilibrium
A projectile is thrown at an angle α to the horizontal with velocity v. It will have the maximum centripetal acceleration
At the start
At the top of the trajectory
As it strikes the ground
Elsewhere
A particle executes a simple harmonic motion. While passing through the mean position, the particle possesses
Maximum kinetic energy and minimum potential energy
Maximum kinetic energy and maximum potential energy
Minimum kinetic energy and maximum potential energy
Minimum kinetic, energy and minimum potential energy
A block of weight 50 kg is placed on a horizontal plane. When a horizontal force of 18 kg is applied, the block is just on the point of motion. The angle of friction is
17° 48'
18° 48'
19° 48'
20° 48'
The horizontal reaction at the support A of the structure shown in below figure, is
Zero
2 t
3 t
1 t
Centre of gravity of a thin hollow cone lies on the axis of symmetry at a height of
One-half of the total height above base
One-third of the total height above base
One-fourth of the total height above base
None of these
The locus of the instantaneous centre of a moving rigid body, is
Straight line
Involute
Centroid
Spiral
A stone is whirled in a vertical circle, the tension in the string, is maximum
When the string is horizontal
When the stone is at the highest position
When the stone is at the lowest position
At all the positions