Moment of inertia of an object does not depend upon
1. mass of object
2. mass distribution
3. angular velocity
4. axis of rotation
A thin uniform circular disc of mass \(M\) and radius \(R\) is rotating in a horizontal plane about an axis passing through its center and perpendicular to its plane with an angular velocity . Another disc of the same dimensions but of mass \(\frac{1}{4}M\) is placed gently on the first disc co-axially. The angular velocity of the system will be:
1. | 2. | ||
3. | 4. |
When a torque acting upon a system is zero, then which of the following will be constant
1. force
2. Linear momentum
3. Angular momentum
4. Linear impulse
A flywheel is in the form of a uniform circular disc of radius 1 m and mass 2 kg. The work which must be done on it to increase its frequency of rotation from 5 rev to 10 rev is approximately
1. 1.5 x J
2. 3.0 x J
3. 1.5 x J
4. 3.0 x J
A constant torque acting on a uniform circular wheel changes its angular momentum from to in 4s. The magnitude of this torque is
1.
2.
3.
4.
Two discs are rotating about their axes, normal to the discs and passing through the centres of the discs. Disc D has 2 kg mass and 0.2 m radius and initial angular velocity of 50 rad s. Disc D has 4 kg mass, 0.1 m radius and initial angular velocity of 200 rad s. The two discs are brought in contact face to face, with their axes of rotation coincident. The final angular velocity (in rad.s) of the system is
1. 60
2. 100
3. 120
4. 40
A body rolls down an inclined plane without slipping. The fraction of total energy associated with its rotation will be
Where k is radius of gyration of the body about an axis passing through centre of mass and R is the radius of the body.
In the following figure, a weight W is attached to a string wrapped round a solid cylinder of mass M mounted on a frictionless horizontal axle at O.
If the weight starts from rest and falls a distance h, then its speed at that instant is
1. Proportional to \(\text R\)
2. Proportional to \(1 \over R\)
3. Proportional to \(1 \over R^2\)
4. Independent of \(\text R\)
A solid cylinder rolls down an inclined plane that has friction sufficient to prevent sliding. The ratio of rotational energy to total kinetic energy is
1.
2.
3.
4.