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
Correct Answer :
B. Q sin θ/P + Q cos θ
Related Questions
A particle moves along a straight line such that distance x traversed in t seconds is given by x = t2(t + 1), the acceleration of the particle, will be
3t3 - 2t
3t2 + 2t
6t - 2
6t + 2
Force polygon method is applicable for
Any coplanar force system
A system of parallel forces only
Concurrent coplanar force system
Non-concurrent coplanar force system
The angular speed of a car taking a circular turn of radius 100 m at 36 km/hr will be
0.1 rad/sec
1 rad/sec
10 rad/sec
100 rad/sec
If the gravitational acceleration at any place is doubled, the weight of a body, will
Be reduced to half
Be doubled
Not be affected
None of these
The time period of a simple pendulum depends on (i) Mass of suspended particle (ii) Length of the pendulum (iii) Acceleration due to gravity The correct answer is
Only (i)
Both (ii) and (iii)
Both (i) and (iii)
All are correct
A system of coplanar forces is in equilibrium when
Force polygon closes
Funicular polygon closes
Both force polygon and funicular polygon close
All the forces are concurrent
Select the correct statement
The body centrode rolls on the space centrode
The space centrode rolls on the body centrode
Both body and space centrodes may role on each other
The body centrode never touches space centrode
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
The instantaneous centre of a member lies at the point of intersection of two lines drawn at the ends of the member such that the lines are inclined to the direction of motion of the ends at
30°
45°
60°
90°
A number of forces acting simultaneously on a particle of a body
May not be replaced by a single force
May be replaced by a single force
May be replaced by a single force through C.G. of the body
May be replaced by a couple
If two forces are in equilibrium, then the forces must (i) Be equal in magnitude (ii) Be opposite in sense (iii) Act along the same line The correct answer is
(i) and (ii)
(i) and (iii)
Only (i)
All (i), (ii) and (iii)
Instantaneous center is at infinity when the angular velocity is
Constant
Zero
Maximum
Minimum
The angular speed of a car while taking a circular turn of radius 100 m at 36 km/hour, is
0.1 radian/sec
1 radian/sec
100 radian/sec
1000 radian/sec
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
A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec²)
15 m/sec
25 m/sec
40 m/sec
50 m/sec
A circular disc rotates at n rpm. The angular velocity of a circular ring of same mass and radius as the disc and to have the same angular momentum is
n rpm
n/2 rpm
n/4 rpm
2n rpm
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
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
1346.3 kN and 1500 kN
1436.2 kN and 1250 kN
1346.3 kN and 1250 kN
1436.2 kN and 1500 kN
The intrinsic equation of catenary is
S = c tan ψ
y = c cosh x/c
y = c cosh ψ
y = c sinh ψ
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 centre of gravity of a triangle is at the point where three
Medians of the triangle meet
Perpendicular bisectors of the sides of the triangle meet
Bisectors of the angle of the triangle meet
None of these
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
Original velocity in the same direction
Half the original velocity in the same direction
Half the original velocity in the opposite direction
Original velocity in the opposite direction
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
The point about which combined motion of rotation and translation of a rigid body takes place, is known as
Virtual centre
Instantaneous centre
Instantaneous axis
Point of rotation
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
½ sec
1 sec
1.2 sec
1.5 sec
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
Zero
30 m
50 m
60 m
The product of mass and velocity of a moving a body, is called
Moment
Momentum
Power
Impulse
P is the force acting on a body whose mass is m and acceleration is f. The equation P - mf= 0, is known as
Equation of dynamics
Equation of dynamic equilibrium
Equation of statics
None of these
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