Angular Acceleration

Q.

wheel is making revolutions about its axis with uniform angular acceleration. Starting from rest, it reaches 100 rev/sec in 4 seconds. Find the angular acceleration.

1. 

2. 

3. 

4. 

Q. A cord of negligible mass is wound round the rim of fly wheel of mass 20 kg and radius 20 cm. A steady pull of 25 N is applied on the cord as shown in the figure. The fly wheel is mounted on a horizontal axle with frictionless bearings. Find KE of the wheel at this point. Assume that the wheel starts from rest.

1. 40 J
2. 50J
3. 60 J
4. 70J

Q. A wheel is rolling on a horizontal plane. At a certain instant, it has a velocity ${}^{\prime }{v}^{\prime }$ and acceleration ${}^{\prime }{a}^{\prime }$ of CM as shown in figure. Acceleration of

1. $A$ is vertically upwards
2. $B$ may be vertically downwards
3. $C$ cannot be horizontal
4. some points on the rim may be horizontal leftwards

Q. In figure (i), half of the meter scale is made of wood while the other half of steel. The wooden part is pivoted at $O$ and a force $F$ is applied at the end of steel part. In figure (ii), the steel part is pivoted at $O$ and the same force is applied at the wooden end.

1. More angular acceleration will be produced in (i)
2. More angular acceleration will be produced in (ii)
3. Same angular acceleration will be produced in both the conditions
4. Information is incomplete

Q. A wheel is making rotations about its axis with uniform angular acceleration. Starting from rest, it reaches 100 rot/s in 4 seconds. It's angular acceleration is

1. $50\frac{rot}{s^2}$
2. $25\frac{rot}{s^2}$
3. $40\frac{rot}{s^2}$
4. $500\pi \frac{radians}{s^2}$