The coefficient of restitution for inelastic bodies is
Zero
One
Between zero and one
More than one
Correct Answer :
A. Zero
Related Questions
In a screw jack, the effort required to lower the load is __________ the effort required to raise the same load.
Less than
Equal to
More than
None of these
A lead ball with a certain velocity is made to strike a wall, it falls down, but rubber ball of same mass and with same velocity strikes the same wall, it rebounds. Select the correct reason from the following:
Both the balls undergo an equal change in momentum
The change in momentum suffered by rubber ball is more than the lead ball
The change in momentum suffered by rubber ball is less than the lead ball
None of the above
The moment of the force P about O as shown in the below figure is 
P × OA
P × OB
P × OC
P × AC
If the gravitational acceleration at any place is doubled, then the weight of a body will be
g/2
g
√2.g
2g
The velocity of a particle (v) moving with simple harmonic motion, at any instant is given by (where r = Amplitude of motion, and y = Displacement of the particle from mean position.)
ω.√(y² - r²)
ω.√(r² - y²)
ω².√(y² - r²)
ω².√(r² - y²)
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p
Work done is said to be zero, when
Some force acts on a body, but displacement is zero
No force acts on a body but some displacement takes place
Either (A) or (B)
None of the above
A single force and a couple acting in the same plane upon a rigid body
Balance each other
Cannot balance each other
Produce moment of a couple
Are equivalent
If rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella
More inclined when moving
Less inclined when moving
More inclined when standing
Less inclined when standing
The unit of force in S.I. system of units is
Dyne
Kilogram
Newton
Watt
Moment of inertia of a circular section about an axis perpendicular to the section is
πd3/16
πd3/32
πd4/32
πd4/64
Mass moment of inertia of a uniform thin rod of mass M and length (l) about its mid-point and perpendicular to its length is
(2/3) Ml2
(1/3) Ml2
(3/4) Ml2
(1/12) Ml2
In ideal machines
Mechanical advantage is greater than velocity ratio
Mechanical advantage is equal to velocity ratio
Mechanical advantage is less than velocity ratio
Mechanical advantage is unity
Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
Area of the triangle
Twice the area of the triangle
Half the area of the triangle
None 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
Coefficient of friction is the
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
A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
2.5 cm
3.0 cm
4.0 cm
5.0 cm
The amplitude is always __________ radius of the circle.
Equal to
Less than
Greater than
None of these
The total momentum of a system of masses (i. e. moving bodies) in any one direction remains constant, unless acted upon by an external force in that direction. This statement is called
Newton's first law of motion
Newton's second law of motion
Principle of conservation of energy
Principle of conservation of momentum
The maximum height of a projectile on a horizontal plane, is
u² sin²α/2g
u² cos²α/2g
u² sin²α/g
u² cos²α/g
The horizontal range of a projectile (R) is given by
R = u² cos2α/g
R = u² sin2α/g
R = u² cosα/g
R = u² sinα/g
A couple produces
Translatory motion
Rotational motion
Combined translatory and rotational motion
None of the above
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 centre of percussion is below the centre of gravity of the body and is at a distance equal to
h/kG
h2/kG
kG2/h
h × kG
When a person, on a bicycle, drives round a curve, he has to lean __________ to maintain equilibrium.
Inward
Outward
Towards front
Towards back
The moment of inertia of a solid sphere of mass m and radius r is
2mr2/3
2mr2/5
mr2
mr2/2
The ratio of static friction to dynamic friction is always
Equal to one
Less than one
Greater than one
None of these
When a body of mass m attains a velocity v from rest in time t, then the kinetic energy of translation is
mv2
mgv2
0.5 mv2
0.5 mgv2
Which of the following statement is incorrect?
A force acting in the opposite direction to the motion of the body is called force of friction
The ratio of the limiting friction to the normal reaction is called coefficient of friction
A machine whose efficiency is 100% is known as an ideal machine
The velocity ratio of a machine is the ratio of load lifted to the effort applied
Centre of gravity of a thin hollow cone lies on the axis at a height of
One-fourth of the total height above base
One-third of the total height above base
One-half of the total height above base
Three-eighth of the total height above the base