A spherical solid ball of mass 1 kg and radius 3cm 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
A ring of mass m and radius r rotates about an axis passing through its centre and perpendicular to its plane with angular velocity ω. Its kinetic energy is
½mr2ω2
mrω2
mr2ω2
½ mr2ω
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
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 momentum of a body with mass(m) moment of inertia (I) and angular velocity (ω)rad/s is equal to
Iω
Iω2
The speed of a homogeneous solid sphere after rolling down an inclined plane of vertical height h from rest without sliding is
A ball of mass 0.25kg attached to the end of a string of length 1.96m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved?
14m/s
3 m/s
3.92 m/s
5 m/s
O is the centre of an equilateral triangle ABC. F1, F2 and F3 are three forces actng along the sides AB, BC and AC as shown in figure. What should be the magnitude of F3, so that the total torque about O is zero?
(F1 - F2)
(F1 + F2)
2(F1 - F2)
A cart of mass M is tied to one end of a massless rope of length 10m. The other end of the rope is in the hands of a man of mass M. The entire system is on a smooth horizontal surface. The man is at x = 0 and the cart at x = 10m. If the man pulls the cart by the rope, the man and the cart will meet at the point
they will never will meet
x = 10 m
x = 5 m
x = 0
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
