HARD
Earn 100

Establish the relation between angular acceleration and linear acceleration.

Important Questions on Rotational Dynamics

EASY
A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to 8×10-4 J by the end of the second revolution after the beginning of the motion?
MEDIUM

One end of a rod of length L=1 m is fixed to a point on the circumference of a wheel of radius R=13 m. The other end is sliding freely along a straight channel passing through the center O of the wheel as shown in the figure below. The wheel is rotating with a constant angular velocity ω (in radian per second) about O.

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The speed of the sliding end P when θ=60° is

EASY
In a uniform circular motion r,V and ω stands for radius vector, linear velocity and angular velocity respectively. Then which of the following is true?
EASY
A force F=(i^+2j^+3k^) N acts at a point (4i^+3j^-k^) m. Then the magnitude of torque about the point (i^+2j^+k^) m will be x  N m.The value of x is..........
MEDIUM
A uniform solid sphere of radius R and radius of gyration K about an axis passing through the centre of mass, is rolling without slipping. Then the fraction of total energy associated with its rotation will be
MEDIUM
A ball is spun with angular acceleration α=6t2-2t where t is in second and α is in rad s-2. At t=0, the ball has angular velocity of 10 rad s-1 and angular position of 4 rad. The most appropriate expression for the angular position of the ball is
EASY
What is the value of tangential acceleration in U.C.M. ?
MEDIUM
A tube of length 50 cm is filled completely with an incompressible liquid of mass 250 g and closed at both ends. The tube is then rotated in horizontal plane about one of its ends with a uniform angular velocity xF rad s-1. If F be the force exerted by the liquid at the other end then the value of x will be _____ .
EASY

The angular speed of truck wheel is increased from 900 rpm to 2460 rpm in 26 seconds. The number of revolutions by the truck engine during this time is ______.

(Assuming the acceleration to be uniform).

EASY

A solid disc of radius a and mass m rolls down without slipping on an inclined plane making an angle θ with the horizontal. The acceleration of the disc will be 2 bgsinθ, where b is _______.  (Round off to the nearest integer)

(g= acceleration due to gravity and θ= angle as shown in figure)

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MEDIUM
The moment of inertia of a ring about an axis passing through the centre and perpendicular to its plane is I. It is rotating with angular velocity ω. Another identical ring is gently placed on it so that their centres coincide. If both the rings are rotating about the same axis then loss in kinetic energy is
MEDIUM
A uniform ring of radius R is moving on a horizontal surface with speed v, then climbs up a ramp of inclination 30° to a height h. There is no slipping in the entire motion. Then, h is
EASY
Obtain the relation between the magnitude of linear acceleration and angular acceleration in circular motion.
HARD
A cylinder of mass, m is allowed to roll on a smooth horizontal table with a spring of spring constant, k attached to it so that it executes SHM about the equilibrium position. What is the time period, T of oscillations?
EASY
A rigid body is rotating with angular velocity ω about an axis of rotation. Let v be the linear velocity of particle which is at perpendicular distance r from the axis of rotation. Then the relation v=ωr implies that
MEDIUM

A ball is rolling without slipping in a spherical shallow bowl (radius R ) as shown in the figure and is executing simple harmonic motion. If the radius of the ball is doubled, then the time period of oscillation

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EASY
Two particle A and B are moving with constant velocities v1=j^ and v2=2i^  respectively in XY plane. At time t=0, the particle A is at co-ordinates (0,0) and B is at (-4,0). The angular velocity of B with respect to A at t=2 s is (all units are in SI)
MEDIUM

Represent the union of two sets by Venn diagram for each of the following.

X={x | x is a prime number between 80 and 100}

Y={y | y is an odd number between 90 and 100}

HARD
A horizontal disk is rotating with angular velocity ' ω '  about a vertical axis passing through its centre. A ball is placed at the centre of groove and pushed slightly. The velocity of ball when it comes out of the groove –


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EASY
The angular speed of a flywheel making 120 rev min-1 is