Which of the following will not be affected if the radius of the sphere is increased while keeping mass constant?
1. Moment of inertia
2. Angular momentum
3. Angular velocity
4. Rotational kinetic energy
Three objects, A : (a solid sphere), B : (a thin circular disk) and C = (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation:
1. WC > WB > WA
2. WA > WB > WC
3. WB > WA > WC
4. WA > WC > WB
The moment of the force, at point (2, 0, -3) about the point (2, -2, -2) is given by:
A solid sphere is in rolling motion. In rolling motion, a body possesses translational kinetic energy (Kt) as well as rotational kinetic energy (Kr) simultaneously. The ratio Kt : (Kt + Kr) for the sphere will be:
A solid sphere is rotating freely about its axis of symmetry in free space. The radius of the sphere is increased keeping its mass the same. Which of the following physical quantities would remain constant for the sphere?
1. Angular velocity
2. Moment of inertia
3. Rotational kinetic energy
4. Angular momentum
A rope is wrapped around a hollow cylinder with a mass of 3 kg and a radius of 40 cm. What is the angular acceleration of the cylinder if the rope is pulled with a force of 30 N?
Two discs of the same moment of inertia are rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities and . They are brought into contact face to face with their axis of rotation coinciding. The expression for loss of energy during this process is:-
Which of the following statements are correct?
(a) Centre of mass of a body always coincides with the centre of gravity of the body
(b) Centre of gravity of a body is the point about which the total gravitational torque on the body is zero
(c) A couple on a body produce both translational and rotation motion in a body
(d) Mechanical advantage greater than one means that small effort can be used to lift a large load
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (b) and (d)
A disc and a solid sphere of the same radius but different masses roll off on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first?
3. Both reach at the same time
4. Depends on their masses
Two rotating bodies A and B of masses m and 2m with moments of inertia and have equal kinetic energy of rotation. If and be their angular momenta respectively, then: