The units of inertia of mass are
kg/m
kg/m2
m4
kg-m2
Correct Answer :
D. kg-m2
Related Questions
A weight W is suspended at the free end of a light member hinged to a vertical wall. If the angle of inclination of the member with the upper wall is θ°, the force introduced in the member, is
W sec θ
W cos θ
W sin θ
W cosec θ
The condition of equilibrium for any system of forces in a plane is
That polygon of forces must close
That resultant couple must be zero
Both (A) and (B)
None of the above
The intrinsic equation of catenary is
S = c tan ψ
y = c cosh x/c
y = c cosh ψ
y = c sinh ψ
A block of weight 50 kg is placed on a horizontal plane. When a horizontal force of 18 kg is applied, the block is just on the point of motion. The angle of friction is
17° 48'
18° 48'
19° 48'
20° 48'
Pick up the correct statement from the following:
Nature plays an important role in the launch of a satellite
The earth's gravity reduces the speed of a satellite by 32 km per second
The gravitational force relents as the satellite climbs higher
All the above
If a particle is projected inside a horizontal tunnel which is 554 cm high with a velocity of 60 m per sec, the angle of projection for maximum range, is
8°
9°
10°
11°
Parallelogram Law of Forces states, if two forces acting simultaneously on a particle be represented in magnitude and direction by two adjacent sides of a parallelogram, their resultant may be represented in magnitude and direction by
Its longer side
Its shorter side
The diagonal of the parallelogram which does not pass through the point of intersection of the forces
The diagonal of the parallelogram which passes through the point of intersection of the forces
The horizontal reaction at the support A of the structure shown in below figure, is
Zero
2 t
3 t
1 t
Two balls of masses 3 kg and 6 kg are moving with velocities of 4 m/sec and 1 m/sec respectively, towards each other along the line of their centers. After impact the 3 kg ball comes to rest. This can happen only if the coefficient of restitution between the balls is
2/3
1/5
3/5
1/3
A pilot flies a small plane in a vertical loop of radius r. At the top of its trajectory he experiences weightlessness. If the acceleration due to gravity is g, the speed of the plane at the top of its trajectory would be
Zero
Infinite
gr
2gr
Work may be defined as
Force × distance
Force × velocity
Force × acceleration
None of these
If a body is acted upon by a number of coplanar non-concurrent forces, it may
Rotate about itself without moving
Move in any one direction
Move in any one direction rotating about itself
All the above
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
0.25
0.50
0.75
1.0
ω rad/sec is the angular velocity of a crank whose radius is r. If it makes θ° with inner dead centre and obliquity of the connecting rod l is , the velocity v of the piston, is given by the equation
ω2 (l cos + r sin tan θ)
ω2 (l sin + r cos φ tan θ)
ω (l sin + r cos tan θ)
ω2 (l sin - r cos θ tan )
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
If a projectile is fired with an initial velocity of 10 m/sec at an angle of 60° to the horizontal, its horizontal and vertical velocity at the highest point of trajectory are
0 and 5 m/sec
5 m/sec and 0
5√3 m/sec and 0
5 and 5√3 m/sec
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°
Two particles have been projected at angles 64° and 45° to the horizontal. If the velocity of projection of first is 10 m/sec, the velocity of projection of the other for equal horizontal ranges is
9.3 m/sec
8.3 m/sec
7.3 m/sec
6.3 m/sec
Joule is the unit of
Work
Force
Power
Torque
Pick up the correct statement from the following:
If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities
If a sphere impinges directly on an equal sphere which is at rest, then a fraction ½(1 - e2) the original kinetic energy is lost by the impact
If two equal spheres which are perfectly elastic impinge at right angles, their direction after impact will still be at right angles
All the above
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
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
Coefficient of friction depends on
Nature of surfaces only
Area of contact only
Both (A) and (B)
None of the above
The force which produces an acceleration of 1 m/sec2 in a mass of one kg, is called
Dyne
Newton
Joule
Erg
According to Law of Triangle of Forces
Three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force
Three forces acting along the sides of a triangle are always in equilibrium
If three forces acting on a, point can be represented in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium
If the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order
The moment of inertia of a hollow circular section whose external diameter is 8 cm and internal diameter is 6 cm, about centroidal axis, is
437.5 cm4
337.5 cm4
237.5 cm4
137.5 cm4
For perfectly elastic bodies, the value of coefficient of restitution is
Zero
0.5
1.0
Between 0 and 1
The tension in a cable supporting a lift
Is more when the lift is moving downwards
Is less when the lift is moving upwards
Remains constant whether its moves downwards or upwards
Is less when the lift is moving downwards
If two forces each equal to T in magnitude act at right angles, their effect may be neutralised by a third force acting along their bisector in opposite direction whose magnitude will be
2 T
1/2 T
√2 T
3 T
Which of the following represents the state of neutral equilibrium?
A cube resting on one edge
A smooth cylinder lying on a curved surface
A smooth cylinder lying on a convex surface
None of the above