A satellite goes on moving along its orbit round the earth due to
Gravitational force
Centrifugal force
Centripetal force
None of these
Correct Answer :
B. Centrifugal force
Related Questions
A shell travelling with a horizontal velocity of 100 m/sec explodes and splits into two parts, one of mass 10 kg and the other of 15 kg. The 15 kg mass drops vertically downward with initial velocity of 100 m/sec and the 10 kg mass begins to travel at an angle to the horizontal of tan1 x, where x is
3/4
4/5
5/3
3/5
A simple pendulum of length 1 has an energy E when its amplitude is A. If its amplitude is increased to 2 A, the energy becomes
E
E/2
2E
4E
Free body diagram is an
Isolated joint with only body forces acting on it
Isolated joint with internal forces acting on it
Isolated joint with all the forces, internal as well as external, acting on it
None of the above
If the resultant of two forces P and Q acting at an angle θ makes an angle α with P, then tan α equals
P sin θ/P - Q cos θ
Q sin θ/P + Q cos θ
P sin θ/P + Q tan θ
Q sin θ/P + Q sin θ
A cube on a smooth horizontal surface
Cannot be in stable equilibrium
Cannot be in neutral equilibrium
Cannot be in unstable equilibrium
Can be in any of these states
The total time of collision and restitution of two bodies, is called
Time of collision
Period of collision
Period of impact
All the above
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 mechanical advantage of the lifting machine is
15
18
20
26
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
For a self-locking machine, the efficiency should be
Less than 60%
50 %
More than 50%
None of these
μ is coefficient of friction. A wheeled vehicle travelling on a circular level track will slip and overturn simultaneously if the ratio of its wheel distance to the height of its centroid, is
μ
2μ
3μ
½μ
A body of weight 14 g appears to weight 13 g when weighed by a spring balance in a moving lift. The acceleration of the lift at that moment was
0.5 m/sec2
0.7 m/sec2
1 m/sec2
1 cm/sec2
In case of S.H.M. the period of oscillation (T), is given by
T = 2ω/π²
T = 2π/ω
T = 2/ω
T = π/2ω
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
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)
The unit of rotational inertia of a body in C.G.S system is
cm4
kg.cm²
gm.cm²
gm.cm3
The intrinsic equation of catenary is
S = c tan ψ
y = c cosh x/c
y = c cosh ψ
y = c sinh ψ
Three forces which act on a rigid body to keep it in equilibrium. The forces must be coplanar and
Concurrent
Parallel
Concurrent parallel
None of these
A ball which is thrown upwards, returns to the ground describing a parabolic path during its flight
Vertical component of velocity remains constant
Horizontal component of velocity remains constant
Speed of the ball remains constant
Kinetic energy of the ball remains constant
Coefficient of friction depends on
Nature of surfaces only
Area of contact only
Both (A) and (B)
None of the above
One half of a vibration of a body, is called
Period time
Oscillation
Beat
Amplitude
A uniform rod 9 m long weighing 40 kg is pivoted at a point 2 m from one end where a weight of 120 kg is suspended. The required force acting at the end in a direction perpendicular to rod to keep it equilibrium, at an inclination 60° with horizontal, is
40 kg
60 kg
10 kg
100 kg
A cable loaded with 0.5 tonne per horizontal metre span is stretched between supports in the same horizontal line 400 m apart. If central dip is 20 m, the minimum tension in the cable, will be
200 tonnes at the centre
500 tonnes at the centre
200 tonnes at the right support
200 tonnes at the left support
If α and u are the angle of projection and initial velocity of a projectile respectively, the horizontal range of the projectile, is
u² sin α/g
u² sin² α/g
u² sin α/2g
u² sin² α/2g
The frequency of oscillation on moon as compared to that on earth, will be
2.44 times more
2.44 times less
3 times less
3 times more
When a body in equilibrium undergoes an infinitely small displacement, work imagined to be done, is known as
Imaginary work
Negative work
Virtual work
None of these
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°
The numbers of funicular polygons which can be drawn to pass through two specified points in the space diagram are
Zero
1
2
Infinity
A ball moving with a velocity of 5 m/sec impinges a fixed plane at an angle of 45° and its direction after impact is equally inclined to the line of impact. If the coefficient of restitution is 0.5, the velocity of the ball after impact will be
0.5 m/sec
1.5 m/sec
2.5 m/sec
3.5 m/sec
Total no of instantaneous centres of a machine having n links, is
n/2
n
(n - 1)
n (n - 1)/2
Instantaneous center is at infinity when the angular velocity is
Constant
Zero
Maximum
Minimum