A round disc of moment of inertia I2 about its axis perpendicular to its plane and passing through its center is placed over another disc of moment of inertia I1 rotating with an angular velocity ω about the same axis. The final angular velocity of the combination of discs is
ω
If a sphere is rolling, the ratio of the translational energy to total kinetic energy is given by
7 : 10
2 : 5
10 : 7
5 : 7
ABC is a right angled triangular plate of uniform thickness. The sides are such that AB > BC as shown in figure. I1 , I2, I3 are moments of inertia about AB, BC and AC respectively. Then which of the following relations is correct ?
I1 = I2 = I3
I2 > I1 > I3
I3 < I2 < I1
I3 > I1 > I2
A particle of mass M is revolving along a circle of radius R and another particle of mass m is revolving in a circle of radius r. If time periods of both particles are same, then the ratio of their angular velocities is
1
R/r
r/R
A ball of mass 0.25 kg attached to the end of a string of length 1.96 m 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 ?
14 m/s
3 m/s
3.92 m/s
5 m/s
If a fly wheel makes 120 rev/min, then its angular speed will be
8 π rad/s
6 π rad/s
4 π rad/s
2 π rad/s
A spherical ball rolls on a table without slipping. Then the fraction of its total energy associated with rotation is
2/5
2/7
3/5
3/7
Two racing cars of masses m and 4m are moving in circles of radii r and 2r respectively. If their speeds are such that each makes a complete circle in the same time. Then the ratio of the angular speeds of the first to the second car is
8 : 1
4 : 1
2 : 1
1 : 1
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 :
g/2
g/3
g/4
2g/3
The moment of inertia of a body about a given axis is 1.2 kg – m2. Initially, the body is at rest, in order to produce a rotational kinetic energy of 1500 J, 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