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4

The masses of two balls are in the ratio of 2 : 1 and their respective velocities are in the ratio of 1 : 2 but in opposite direction before impact. If the coefficient of restitution is ½, the velocities of separation of the balls will be equal to

A. Original velocity in the same direction

B. Half the original velocity in the same direction

C. Half the original velocity in the opposite direction

D. Original velocity in the opposite direction

Correct Answer :

D. Original velocity in the opposite direction


Related Questions

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4

When a circular wheel rolls on a straight track, then the shape of body centrode and space centrode respectively are

A. Straight line and parabola

B. Straight line and circle

C. Circle and straight line

D. Circle and parabola

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4

A particle is executing simple harmonic motion in a line 1.0 m long. If the time of one complete vibration is 1 sec, then the maximum velocity of the particle is

A. 1.00 m/sec

B. 1.57 m/sec

C. 3.14 m/sec

D. 6.28 m/sec

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4

For lifting a load of 50 kg through a distance of 2.5 cm, an effort of 12.5 kg is moved through a distance of 40 cm. The efficiency of the lifting machine, is

A. 60 %

B. 65 %

C. 70 %

D. 75 %

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4

Two shots fired simultaneously from the top and bottom of a vertical tower with elevations of 30° and 45° respectively strike a target simultaneously. If horizontal distance of the target from the tower is 1000 m, the height of the tower is

A. 350 m

B. 375 m

C. 400 m

D. 425 m

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4

The direction of projection should bisect the angle between the inclined plane and the vertical for a range of a projectile on inclined plane

A. To be zero

B. To be maximum

C. To be minimum

D. None of these

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4

The height at which the end of a rope of length l should be tied so that a man pulling at the other end may have the greatest tendency to overturn the pillar, is

A. ¾ l

B. ½ l

C. l/√2

D. 2/√3 l

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4

Centre of gravity of a thin hollow cone lies on the axis of symmetry at a height of

A. One-half of the total height above base

B. One-third of the total height above base

C. One-fourth of the total height above base

D. None of these

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4

A heavy ladder resting on a floor and against a vertical wall may not be in equilibrium, if

A. Floor is smooth and the wall is rough

B. Floor is rough and the wall is smooth

C. Floor and wall both are smooth surfaces

D. Floor and wall both are rough surfaces

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4

If the given forces P₁, P₂, P₃ and P₄ are such that the force polygon does not close, then the system will

A. Be in equilibrium

B. Always reduce to a resultant force

C. Always reduce to a couple

D. Both (A) and (C)

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4

In simple harmonic motion, acceleration of a particle is proportional to

A. Rate of change of velocity

B. Displacement

C. Velocity

D. Direction

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4

Instantaneous center is at infinity when the angular velocity is

A. Constant

B. Zero

C. Maximum

D. Minimum

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4

From a solid cylinder of height 8 cm and radius 4 cm, a right circular cone is scooped out on the same base and having the same height as that of the cylinder. The C.G. of the remainder is at a height of

A. 4.5 cm

B. 5.0 cm

C. 5.25 cm

D. 5.5 cm

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4

The unit of impulse, is

A. kg.m/sec

B. kg.m/sec

C. kg.m/sec2

D. kg.m/sec

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4

A particle is dropped from the top of a tower 60 m high and another is projected upwards from the foot of the tower to meet the first particle at a height of 15.9 m. The velocity of projection of the second particle is

A. 16 m/sec

B. 18 m/sec

C. 20 m/sec

D. 22 m/sec

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4

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 tension in the string is

A. 17.5 kg

B. 19.5 kg

C. 22.5 kg

D. 25 kg

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4

The masses of two balls are in the ratio of 2 : 1 and their respective velocities are in the ratio of 1 : 2 but in opposite direction before impact. If the coefficient of restitution is ½, the velocities of separation of the balls will be equal to

A. Original velocity in the same direction

B. Half the original velocity in the same direction

C. Half the original velocity in the opposite direction

D. Original velocity in the opposite direction

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4

Three forces which act on a rigid body to keep it in equilibrium. The forces must be coplanar and

A. Concurrent

B. Parallel

C. Concurrent parallel

D. None of these

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4

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:

A. 40 g

B. 60 g

C. 80 g

D. 100 g

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4

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

A. 50

B. 55

C. 60

D. 65

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4

A disc of mass 4 kg, radius 0.5 m and moment of inertia 3 kgm² rolls on a horizontal surface so that its center moves with speed 5 m/see. Kinetic energy of the disc is

A. 50 J

B. 150 J

C. 200 J

D. 400 J

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4

The displacement of a particle which moves along a straight line is given by S = 4t3 + 3t2- 10 where S is in meters and t is in seconds. The time taken by the particle to acquire a velocity of 18 m/sec from rest, is

A. ½ sec

B. 1 sec

C. 1.2 sec

D. 1.5 sec

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4

A marble ball is rolled on a smooth floor of a room to hit a wall. If the time taken by the ball in returning to the point of projection is twice the time taken in reaching the wall, the coefficient of restitution between the ball and the wall, is

A. 0.25

B. 0.50

C. 0.75

D. 1.0

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4

A cable loaded with 10 kN/m of span is stretched between supports in the same horizontal line 100 m apart. If the central dip is 10 m, then the maximum and minimum pull in the cable respectively are

A. 1346.3 kN and 1500 kN

B. 1436.2 kN and 1250 kN

C. 1346.3 kN and 1250 kN

D. 1436.2 kN and 1500 kN

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4

The resultant of two forces acting at right angles is √34 kg and acting at 60° is 70 kg. The forces are

A. 1 kg and 4 kg

B. 2 kg and 3 kg

C. √3 kg and √5 kg

D. 3 kg and 5 kg

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4

A system of coplanar forces acting on a rigid body can be reduced to

A. One force only

B. One couple only

C. One force and one couple only

D. None of the above

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4

The C.G. of a right circular cone lies on its axis of symmetry at a height of

A. h/2

B. h/3

C. h/4

D. h/5

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4

The angular speed of a car taking a circular turn of radius 100 m at 36 km/hr will be

A. 0.1 rad/sec

B. 1 rad/sec

C. 10 rad/sec

D. 100 rad/sec

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4

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

A. g/2

B. g/3

C. g/4

D. g/5

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4

The motion of a particle is described by the relation x = t2- 10t + 30, where x is in metres and t in seconds. The total distance travelled by the particle from t = 0 to t = 10 seconds would be

A. Zero

B. 30 m

C. 50 m

D. 60 m

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4

A geo-stationary satellite is one which orbits the earth with a velocity of rotation of

A. Moon

B. Earth

C. Sun

D. Pole