Newtons Law of Motion is:
Everybody continues in its state of rest or of uniform motion in a straight line, unless it is acted upon by some external force
The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
To every action, there is always an equal and opposite reaction
All the above
Correct Answer :
D. All the above
Related Questions
A square hole is punched out of a circular lamina, the diagonal of the square being the radius of the circle. If r is the radius of the circle, the C.G. of the remainder from the corner of the square on the circumference will be
[r (π + 0.25)]/(π - 0.5)
[r (π - 0.5)]/(π + 0.25)
[r (π - 0.25)]/(π - 0.5)
[r (π + 0.25)]/(π + 0.5)
A bullet weighing 10 gm moves with a velocity of l km/sec. Its kinetic energy is (i) 5000 Nm (ii) 5000 kg.m (iii) 5000 J The correct answer is
Only (ii)
Both (i) and (iii)
Both (ii) and (iii)
All (i), (ii) and (iii)
If the horizontal range is 2.5 times the greatest height, the angle of projection of the projectile, is
57°
58°
59°
60°
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 horizontal reaction at the support A of the structure shown in below figure, is
Zero
2 t
3 t
1 t
A string of length 90 cm is fastened to two points A and B at the same level 60 cm apart. A ring weighing 120 g is slided on the string. A horizontal force P is applied to the ring such that it is in equilibrium vertically below B. The value of P is:
40 g
60 g
80 g
100 g
For a given velocity of a projectile, the range is maximum when the angle of projection is
30°
45°
90°
0°
The resultant of two forces acting at right angles is 5 kgf and if they act at an angle of 60°, it is 37 kgf. The magnitudes of the forces are:
2 kgf, 3 kgf
3 kgf, 4 kgf
4 kgf, 5 kgf
5 kgf, 3 kgf
The angles between two forces to make their resultant a minimum and a maximum respectively are
0° and 90°
180° and 90°
90° and 180°
180° and 0°
One end of a light string 4 m in length is fixed to a point on a smooth wall and the other end fastened to a point on the surface of a smooth sphere of diameter 2.25 m and of weight 100 kg. The reaction between the sphere and the wall of the arrangement made is
102.5 kg
105.5 kg
108.5 kg
110 kg
The maximum velocity of a body vibrating with a simple harmonic motion of amplitude 150 mm and frequency 2 vibrations/sec, is
188.5 m/sec
18.85 m/sec
1.885 m/sec
0.18845 m/sec
A particle moves in a straight line and its position is defined by the equation x = 6 t² - t3 where t is expressed in seconds and x in meters. The maximum velocity during the motion is
6 m/sec
12 m/sec
24 m/sec
48 m/sec
Williot-Mohr diagram is used to determine deflection in
Trusses only
Beam only
Rigid frames only
Any type of structure
Two parallel forces 20 kg and 15 kg act. In order that the distance of the resultant from 20 kg force may be the same as that of the former resultant was from 15 kg, the 20 kg force is diminished by
5.5 kg
6.25 kg
8.75 kg
10.5 kg
Maximum efficiency of a screw jack for the angle of friction θ, is
sin θ/(1 + sin θ)
(1 - sin θ)/sin θ
(1 + sin θ)/(1 - sin θ)
(1 - sin θ)/(1 + sin θ)
A retarding force on a body does not
Change the motion of the body
Retard the motion of the body
Introduce the motion of the body
None of these
For a particle moving with a simple harmonic motion, the frequency is
Directly proportional to periodic time
Inversely proportional to periodic time
Inversely proportional to its angular velocity
Directly proportional to its angular velocity
The graphical method of determining the forces in the members of a truss is based on
Method of joint
Method of section
Either method
None of the two methods
Two forces of 6 Newtons and 8 Newtons which are acting at right angles to each other, will have a resultant of
5 Newtons
8 Newtons
10 Newtons
12 Newtons
A spring scale in a stationary lift shows a reading of 60 kg for a man standing on it. If the lift starts descending at an acceleration of g/5, the scale reading would be
48 kg
60 kg
72 kg
None of these
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
When a body of mass M1 is hanging freely and another of mass M2 lying on a smooth inclined plane(α) are connected by a light index tensile string passing over a smooth pulley, the acceleration of the body of mass M1, will be given by
g(M1 + M2 sin α)/(M1 + M2) m/sec
g(M1 - M2 sin α)/(M1 + M2) m/sec²
g(M2 + M1 sin α)/(M1 + M2) m/sec²
g(M2 × M1 sin α)/(M2 - M1) m/sec²
A particle is dropped from a height of 3 m on a horizontal floor, which has a coefficient of restitution with the ball of 1/2. The height to which the ball will rebound after striking the floor is
0.5 m
0.75 m
1.0 m
1.5 m
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
If α is the angular acceleration of a compound pendulum whose angular displacement is θ, the frequency of the motion is
2π √(α/θ)
(1/2π) √(α/θ)
4π √(α/θ)
2π √(α - θ)
A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The velocity ratio of the lifting machine is
50
55
60
65
The velocity of a moving body, is
A vector quantity
A scalar quantity
A constant quantity
None of these
If the resultant of two forces has the same magnitude as either of the force, then the angle between the two forces is
30°
45°
60°
120°
The direction of projection should bisect the angle between the inclined plane and the vertical for a range of a projectile on inclined plane
To be zero
To be maximum
To be minimum
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