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
50 J
150 J
200 J
400 J
Correct Answer :
C. 200 J
Related Questions
A system of coplanar forces acting on a rigid body can be reduced to
One force only
One couple only
One force and one couple only
None of the above
A force P of 50 N and another force Q of unknown magnitude act at 90° to each other. They are balanced by a force of 130 N. The magnitude of Q is
60 N
80 N
100 N
120 N
A glass ball is shot to hit a wall from a point on a smooth floor. If the ball returns back to the point of projection in twice the time taken in reaching the wall, the coefficient of restitution between the glass ball and the wall is
0.25
0.33
0.40
0.50
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
g/2
g/3
g/4
g/5
The shape of a suspended cable for a uniformly distributed load over it is
Circular
Parabolic
Catenary
Cubic parabola
The bending moment in an arch is proportional to
Vertical ordinate of funicular polygon
Vertical ordinate of the arch
Intercept between the arch axis and the funicular polygon
None of these
The velocity of a body fallen from height h, on reaching the ground is given by
v = 2gh
v = 2gh2
v = √(2gh)
v = 1/√(2gh)
In a simple harmonic motion, the position of equilibrium is always
Stable
Unstable
Neutral
None of the above
The unit of force in C.G.S. system of units, is called
Dyne
Newton
Kg
All the above
If the horizontal range is 2.5 times the greatest height, the angle of projection of the projectile, is
57°
58°
59°
60°
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
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 resolved part of the resultant of two forces inclined at an angle θ in a given direction is
Algebraic sum of the resolved parts of the forces in the direction
Arithmetical sum of the resolved parts of the forces in the direction
Difference of the forces multiplied by cosine θ°
Sum of the forces multiplied by the tangent θ°
The load shared by the member BC of the structure shown in below figure is
23 t
32 t
4 t
3 t
If g1 and g2 are the gravitational accelerations on two mountains A and B respectively, the weight of a body when transported from A to B will be multiplied by
g1
g2
g1/g2
g2/g1
Periodic time of body moving with simple harmonic motion, is
Directly proportional to its angular velocity
Directly proportional to the square of its angular velocity
Inversely proportional to the square of its angular velocity
Inversely proportional to its angular velocity
For a self-locking machine, the efficiency should be
Less than 60%
50 %
More than 50%
None of these
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
The following statement is one of the laws of Dynamic friction
The force of friction always acts in a direction opposite to that in which a body is moving
The magnitude of the kinetic friction bears a constant ratio to the normal reaction between two surfaces. The ratio being slightly less than that in the case of limiting friction
For moderate speeds the force of friction remains constant but decreases slightly with the increase of speed
All the above
A heavy ladder resting on a floor and against a vertical wall may not be in equilibrium, if
Floor is smooth and the wall is rough
Floor is rough and the wall is smooth
Floor and wall both are smooth surfaces
Floor and wall both are rough surfaces
When a body of mass M1 is hanging freely and another of mass M2 lying on a smooth inclined plane(α) are connected by a light index tensile string passing over a smooth pulley, the acceleration of the body of mass M1, will be given by
g(M1 + M2 sin α)/(M1 + M2) m/sec
g(M1 - M2 sin α)/(M1 + M2) m/sec²
g(M2 + M1 sin α)/(M1 + M2) m/sec²
g(M2 × M1 sin α)/(M2 - M1) m/sec²
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
A stone of mass 1 kg is tied to a string of length 1 m and whirled in a horizontal circle at a constant angular speed 5 rad/sec. The tension in the string is,
5 N
10 N
15 N
25 N
Engineer's units of force, is
Newton in absolute units
Dyne in absolute units
Newton and dyne in absolute units
All the above
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:
40 g
60 g
80 g
100 g
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
From the circular plate of a diameter 6 cm is cut out a circular plate whose diameter is equal to radius of the plate. The C.G. of the remainder shifts from the original position through
0.25 cm
0.50 cm
0.75 cm
1.00 cm
A block in the shape of a parallelepiped of sides 1m × 2m × 3m lies on the surface. Which of the faces gives maximum stable block?
1 m × 2 m
2 m × 3 m
1 m × 3 m
Equally stable on all faces
The shape of a suspended cable under its own weight, is
Parabolic
Circular
Catenary
Elliptical
Which one of the following laws is not applicable to a simple pendulum?
The time period does not depend on its magnitude
The time period is proportional to its length l
The time period is proportional to l, where l is length
The time period is inversely proportional to g, where g is the acceleration due to gravity