A spherical solid ball of mass 1 kg and radius 3 cm is rotating about an axis passing through its centre with an angular velocity of 50 rad s-1. The kinetic energy of rotation is
9/8 j
9/20 j
90 j
4500 j
The rate of change of angular momentum is called
force
torque
impulse
none of these
A thin, uniform circular ring is rolling down an inclined plane of inclination 30º without slipping.Its linear acceleration along the inclined plane will be
A solid sphere, disc and solid cylinder all of the same mass and made of the same material are allowed to roll down (from rest) on the inclined plane, then
solid sphere reaches the bottom first
solid sphere reaches the bottom last
disc will reach the bottom first
all reach the botom at the same time
A constant torque acting on a uniform circular wheel changes its angular momentum from A to 4A in 4 seconds. The magnitude of this torque is
A
4 A
12 A
The angular speed of an engine wheel making 90 rev/min is
1.5 π rad/s
3 π rad /s
4.5 π rad /s
6 π rad /s
The angular speed of a body is expressed in
ms-1
rad
rad s-1
N m-1
ABC is a triangular plate of uniform thickness. The sides are in the ratio shown in the figure. IAB - IBC and ICA are the moments of inertia of the plate about AB, BC and CA as axes respectively. Which one of the following relations is correct?
IAB > IBC
IBC > IAC
IAB + IBC = ICA
ICA is maximum
The moment of inertia of a body about a given axis is 1.2kg-m2. Initially, the body is at rest. In order to produce a rotational kinetic energy of 1500J, an angular acceleration of 25 rad/s2 must be applied about that axis for a duration of
4 s
2 s
8 s
10 s
Choose the correct statement:
The moment of intertia of a body is a scalar
The moment of intertia is expressed in kg m-2
The moment of intertia of a body is unique.
The moment of intertia of a body can't be measured.
