The resultant of two forces P and Q acting at an angle θ, is
P2 + Q2 + 2P sin θ
P2 + Q2 + 2PQ cos θ
P2 + Q2 + 2PQ tan θ
√(P2 + Q2 + 2PQ cos θ)
Correct Answer :
D. √(P2 + Q2 + 2PQ cos θ)
Related Questions
To double the period of oscillation of a simple pendulum
The mass of its bob should be doubled
The mass of its bob should be quadrupled
Its length should be quadrupled
Its length should be doubled
The angle which an inclined surface makes with the horizontal when a body placed on it is on the point of moving down, is called
Angle of repose
Angle of friction
Angle of inclination
None of these
A 2 m long ladder rests against a wall and makes an angle of 30° with the horizontal floor. Where will be the instantaneous center of rotation when the ladder starts slipping? (i) 1.0 in from the wall (ii) 1.732 m from the wall (iii) 1.0 m above the floor (iv) 1.732 m above the floor The correct answer is
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(i) and (iv)
(ii) and (iii)
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Pick up the incorrect statement from the following. In a simple harmonic motion
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Acceleration is minimum at the end of the stroke
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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
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The condition for a lifting machine to be reversible is that its efficiency should be
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More than 50%
More than 66.67%
Equal to 100%
If G is the Gauge of track, v is velocity of the moving vehicle, g is the acceleration due to gravity and r is the radius of a circular path, the required super elevation is
gv²/Gr
Gr²/gr
Gr²/gv²
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Total no of instantaneous centres of a machine having n links, is
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n
(n - 1)
n (n - 1)/2
The horizontal reaction at the support A of the structure shown in below figure, is
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2 t
3 t
1 t
The gravitational force makes a satellite go round the earth in a circular orbit, if it is projected with an initial velocity of
8.04 km/sec at a height of 285 km
11.11 km/sec at a height of 37,400 km
11.26 km/sec, the satellite escapes the pull of the earth
All the above
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2.0 cm
1.5 cm
1.0 cm
0.5 cm
A train weighing 196 tonnes experiences a frictional resistance of 5 11/22 per tonne. The speed of the train at the top of a down gradient 1 in 78.4 is 36 km/hour. The speed of the train after running 1 km down the slope, is
5 √10 m/sec
10 √5 m/sec
5 √3 m/sec
3 √5 m/sec
A vehicle weighing w kg is to run on a circular curve of radius r. If the height of its centre of gravity above the road level is h and the distance between the centres of wheels is 2a, the maximum velocity, in order to avoid over turning, will be
gra/h
√(gra/h)
3√(gra/h)
4√(gra/h)
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
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μ
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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
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19.5 kg
22.5 kg
25 kg
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Zero
1
2
Infinity
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Directly proportional to the square of its angular velocity
Inversely proportional to the square of its angular velocity
Inversely proportional to its angular velocity
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Moon
Earth
Sun
Pole
A ball moving on a smooth horizontal table hits a rough vertical wall, the coefficient of restitution between ball and wall being 1/3. The ball rebounds at the same angle. The fraction of its kinetic energy lost is
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1/9
8/9
Time period and length of a seconds pendulum respectively are
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1 sec and 92.7 cm
2 sec and 99.4 cm
2 sec and 92.7 cm
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ω2 (l sin + r cos φ tan θ)
ω (l sin + r cos tan θ)
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In a lifting machine a weight of 5 kN is lifted through 200 mm by an effort of 0.1 kN moving through 15 m. The mechanical advantage and velocity ratio of the machine are respectively
50 and 75
75 and 50
75 and 75
50 and 50
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Dyne
Newton
Joule
Erg
A rigid body is in a stable equilibrium if the application of any force
Can raise the CG of the body but cannot lower it
Tends to lower the CG of the body
Neither raises nor lowers the CG of the body
None of above
A body is said to move with Simple Harmonic Motion if its acceleration, is
Always directed away from the centre, the point of reference
Proportional to the square of the distance from the point of reference
Proportional to the distance from the point of reference and directed towards it
Inversely proportion to the distance from the point of reference
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
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0.50
0.40
0.67
1.00
The beam shown in below figure is supported by a hinge at A and a roller at B. The reaction RA of the hinged support A of the beam, is 
10.8 t
10.6 t
10.4 t
10.2 t
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Change the motion of the body
Retard the motion of the body
Introduce the motion of the body
None of these