A body of mass m moving with a constant velocity v strikes another body of same mass moving with same velocity but in opposite direction. The common velocity of both the bodies after collision is
v
2v
4v
8v
Correct Answer :
B. 2v
Related Questions
Kinetic friction is the
Tangent of angle between normal reaction and the resultant of normal reaction and the limiting friction
Ratio of limiting friction and normal reaction
The friction force acting when the body is just about to move
The friction force acting when the body is in motion
When a person, on a bicycle, drives round a curve, he has to lean __________ to maintain equilibrium.
Inward
Outward
Towards front
Towards back
The linear velocity of a body rotating at ω rad/s along a circular path of radius r is given by
ω/r
ω.r
ω2/r
ω2.r
The rate of change of displacement of a body is called
Velocity
Acceleration
Momentum
None of these
The skidding away of the vehicle on a level circular path can be avoided if the force of friction between the wheels and the ground is __________ the centrifugal force.
Less than
Greater than
Equal to
None of these
Which one of the following statements is not correct?
The tangent of the angle of friction is equal to coefficient of friction
The angle of repose is equal to angle of friction
The tangent of the angle of repose is equal to coefficient of friction
The sine of the angle of repose is equal to coefficient to friction
The moment of inertia of a thin rod of mass m and length l, about an axis through its centre of gravity and perpendicular to its length is
ml2/4
ml2/ 6
ml2/8
ml2/12
The amplitude is always __________ radius of the circle.
Equal to
Less than
Greater than
None of these
The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane __________ the angle of friction.
Equal to
Less than
Greater than
None of these
The moment of inertia of a rectangular section 3 cm wide and 4 cm deep about X-X axis is
9 cm4
12 cm4
16 cm4
20 cm4
The centre of gravity of a triangle lies at the point of
Concurrence of the medians
Intersection of its altitudes
Intersection of bisector of angles
Intersection of diagonals
In the lever of third order, load W, effort P and fulcrum F are oriented as follows
W between P and F
F between W and P
P between W and F
W, P and F all on one side
The bellow figure shows the three coplanar forces P, Q and R acting at a point O. If these forces are in equilibrium, then 
P/sin β = Q/sin α = R/sin
P/sin α = Q/sin β = R/sin
P/sin = Q/sin α = R/sin β
P/sin α = Q/sin = R/sin β
If a body is acted upon by a number of coplanar non-concurrent forces, it may
Rotate about itself without moving
Move in any one direction rotating about itself
Be completely at rest
All of these
A framed structure is perfect, if the number of members are __________ (2j - 3), where j is the number of joints.
Equal to
Less than
Greater than
None of these
The coefficient of friction depends upon
Nature of surfaces
Area of contact
Shape of the surfaces
All of the above
Moment of inertia of a circular section about an axis perpendicular to the section is
πd3/16
πd3/32
πd4/32
πd4/64
Varingon's theorem of moments states that if a number of coplanar forces acting on a particle are in equilibrium, then
Their algebraic sum is zero
Their lines of action are at equal distances
The algebraic sum of their moments about any point in their plane is zero
The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.
According to parallel axis theorem, the moment of inertia of a section about an axis parallel to the axis through centre of gravity (i.e. IP) is given by(where, A = Area of the section, IG = Moment of inertia of the section about an axis passing through its C.G., and h = Distance between C.G. and the parallel axis.)
IP = IG + Ah2
IP = IG - Ah2
IP = IG / Ah2
IP = Ah2 / IG
One joule means that
Work is done by a force of 1 N when it displaces a body through 1 m
Work is done by a force of 1 kg when it displaces a body through 1 m
Work is done by a force of 1 dyne when it displaces a body through 1 cm
Work is done by a force of 1 g when it displaces a body through 1 cm
According to the law of moments, if a number of coplanar forces acting on a particle are in equilibrium, then
Their algebraic sum is zero
Their lines of action are at equal distances
The algebraic sum of their moments about any point in their plane is zero
The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.
In determining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than
Two members with unknown forces of the frame
Three members with unknown forces of the frame
Four members with unknown forces of the frame
Three members with known forces of the frame
A particle moves along a straight line such that distance (x) traversed in t seconds is given by x = t² (t - 4), the acceleration of the particle will be given by the equation
6t² - 8t
3t² + 2t
6f - 8
6f - 4
The range of projectile on a downward inclined plane is ________ the range on upward inclined plane for the same velocity of projection and angle of projection.
Less than
More than
Equal to
None of These
The impact between two lead spheres is approximately equal to an __________ impact.
Elastic
Inelastic
Solid
None of these
In ideal machines, mechanical advantage is __________ velocity ratio.
Equal to
Less than
Greater than
None of these
The moment of inertia of a thin spherical shell of mass m and radius r, about its diameter is
mr2/3
2mr2/3
2mr2/5
3mr2/5
Non-coplanar non-concurrent forces are those forces which
Meet at one point, but their lines of action do not lie on the same plane
Do not meet at one point and their lines of action do not lie on the same plane
Do not meet at one point but their lines of action lie on the same plane
None of the above
The moment of inertia of a sphere of mass m and radius r, about an axis tangential to it, is
2mr2/3
2mr2/5
7mr2/3
7mr2/5
The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by
P + Q
P - Q
P / Q
Q / P