In an orbital motion, the angular momentum vector is
1. Along the radius vector
2. Parallel to the linear momentum
3. In the orbital plane
4. Perpendicular to the orbital plane
A particle of mass m moves with a constant velocity along 3 different paths, DE,OA and BC. Which of the following statements is not correct about its angular momentum about point O?
1. | It is zero when it is at A and moving along OA. |
2. | The same at all points along the line DE. |
3. | Of the same magnitude but oppositely directed at B and D. |
4. | Increases as it moves along the line BC. |
A particle of mass 0.2 kg is moving in a circle of radius 1m with
f=2/π rps, then its angular momentum is-
(A) 0.8 kgm2/s (B) 2 kgm2/s
(C) 8 kgm2/s (D) 16 kgm2/s
A sphere is rolling down a plane of inclination θ to the horizontal. The acceleration of its centre down the plane is
1. g sin θ
2. less than g sin θ
3. greater than g sin θ
4. zero
A bob of mass m attached to an inextensible string of length l is suspended from vertical support. The bob rotates in a horizontal circle with an angular speed ω rad/s about the vertical. About the point of suspension.
1. | Angular momentum is conserved |
2. | Angular momentum changes in magnitude but not in the direction |
3. | Angular momentum changes in direction but not in magnitude |
4. | Angular momentum changes both in direction and magnitude |
In free space, a rifle of mass M shoots a bullet of mass m at a stationary block of mass M at a distance D away from it. When the bullet has moved through a distance d towards the block, the centre of mass of the bullet-block system is at a distance of:
1. D−dM+m from the bullet
2. md+MDM+m from the block
3. 2md+MDM+m from the block
4. (D−d)MM+m from the bullet
Blocks A and B are resting on a smooth horizontal surface given equal speeds of 2 m/s in the opposite sense as shown in the figure.
At t = 0, the position of blocks are shown, then the coordinates of centre of mass at t = 3s will be
1. (1, 0)
2. (3, 0)
3. (5, 0)
4. (2.25, 0)
A wheel is at rest. Its angular velocity increases uniformly and becomes 80 rad/s after 5 s. The total angular displacement is
1. 800 rad
2. 400 rad
3. 200 rad
4. 100 rad
A force−Fˆk acts on O, the origin of the coordinate system. The torque at the point (1, -1) will be:
1. -F(ˆi+ˆj)
2. F(ˆi+ˆj)
3. -F(ˆi-ˆj)
4. F(ˆi-ˆj)
Moment of inertia of an object does not depend upon
1. | mass of object |
2. | mass distribution |
3. | angular velocity |
4. | axis of rotation |