Angular Momentum and its Conservation for a Rigid Body
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365663 A circular disc is mounted on a vertical frictionless axle. Its radius is \(r = 4\;m\) and moment of inertial \(I = 100\;kg\;{m^2}\). Intially the disc is at rest. A \(30\;kg\) boy stands on the edge and begins to walk along the edge at a speed of \(2\;m{s^{ - 1}}\) relative to the ground. Find the angular velocity of the disc.

1 \(2.4\,\,rad/{s^2}\)
2 \(4.8\,\,rad/{s^2}\)
3 \(8\,\,rad/{s^2}\)
4 \(1\,\,rad/{s^2}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365664 A disc of mass \(m_{0}\) rotates freely about a fixed horizontal axis through its center. A thin cotton pad is fixed to its rim, which can absorb water. The mass of water dripping onto the pad is \(\mu\) per second. After what time will the angular velocity of the disc get reduced to half of its initial value:
supporting img

1 \(\dfrac{m_{0}}{\mu}\)
2 \(\dfrac{m_{0}}{2 \mu}\)
3 \(\dfrac{2 m_{0}}{\mu}\)
4 \(\dfrac{3 m_{0}}{\mu}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365665 If the torque of the rotational motion will be zero, then the constant quantity will be

1 angular momentum
2 linear momentum
3 angular acceleration
4 centripetal acceleration
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365666 A thin uniform circular disc of mass \(M\) and radius \(\mathrm{R}\) is rotating in a horizontal plane about an axis passing through its centre and perpendicular to the plane with angular velocity \(\omega\). Another disc of same mass but half the radius is gently placed over it coaxially. The angular speed of the composite disc will be :

1 \((5 / 4) \omega\)
2 \((4 / 5) \omega\)
3 \((2 / 5) \omega\)
4 \((5 / 2) \omega\)
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PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365663 A circular disc is mounted on a vertical frictionless axle. Its radius is \(r = 4\;m\) and moment of inertial \(I = 100\;kg\;{m^2}\). Intially the disc is at rest. A \(30\;kg\) boy stands on the edge and begins to walk along the edge at a speed of \(2\;m{s^{ - 1}}\) relative to the ground. Find the angular velocity of the disc.

1 \(2.4\,\,rad/{s^2}\)
2 \(4.8\,\,rad/{s^2}\)
3 \(8\,\,rad/{s^2}\)
4 \(1\,\,rad/{s^2}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365664 A disc of mass \(m_{0}\) rotates freely about a fixed horizontal axis through its center. A thin cotton pad is fixed to its rim, which can absorb water. The mass of water dripping onto the pad is \(\mu\) per second. After what time will the angular velocity of the disc get reduced to half of its initial value:
supporting img

1 \(\dfrac{m_{0}}{\mu}\)
2 \(\dfrac{m_{0}}{2 \mu}\)
3 \(\dfrac{2 m_{0}}{\mu}\)
4 \(\dfrac{3 m_{0}}{\mu}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365665 If the torque of the rotational motion will be zero, then the constant quantity will be

1 angular momentum
2 linear momentum
3 angular acceleration
4 centripetal acceleration
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365666 A thin uniform circular disc of mass \(M\) and radius \(\mathrm{R}\) is rotating in a horizontal plane about an axis passing through its centre and perpendicular to the plane with angular velocity \(\omega\). Another disc of same mass but half the radius is gently placed over it coaxially. The angular speed of the composite disc will be :

1 \((5 / 4) \omega\)
2 \((4 / 5) \omega\)
3 \((2 / 5) \omega\)
4 \((5 / 2) \omega\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365663 A circular disc is mounted on a vertical frictionless axle. Its radius is \(r = 4\;m\) and moment of inertial \(I = 100\;kg\;{m^2}\). Intially the disc is at rest. A \(30\;kg\) boy stands on the edge and begins to walk along the edge at a speed of \(2\;m{s^{ - 1}}\) relative to the ground. Find the angular velocity of the disc.

1 \(2.4\,\,rad/{s^2}\)
2 \(4.8\,\,rad/{s^2}\)
3 \(8\,\,rad/{s^2}\)
4 \(1\,\,rad/{s^2}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365664 A disc of mass \(m_{0}\) rotates freely about a fixed horizontal axis through its center. A thin cotton pad is fixed to its rim, which can absorb water. The mass of water dripping onto the pad is \(\mu\) per second. After what time will the angular velocity of the disc get reduced to half of its initial value:
supporting img

1 \(\dfrac{m_{0}}{\mu}\)
2 \(\dfrac{m_{0}}{2 \mu}\)
3 \(\dfrac{2 m_{0}}{\mu}\)
4 \(\dfrac{3 m_{0}}{\mu}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365665 If the torque of the rotational motion will be zero, then the constant quantity will be

1 angular momentum
2 linear momentum
3 angular acceleration
4 centripetal acceleration
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365666 A thin uniform circular disc of mass \(M\) and radius \(\mathrm{R}\) is rotating in a horizontal plane about an axis passing through its centre and perpendicular to the plane with angular velocity \(\omega\). Another disc of same mass but half the radius is gently placed over it coaxially. The angular speed of the composite disc will be :

1 \((5 / 4) \omega\)
2 \((4 / 5) \omega\)
3 \((2 / 5) \omega\)
4 \((5 / 2) \omega\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365663 A circular disc is mounted on a vertical frictionless axle. Its radius is \(r = 4\;m\) and moment of inertial \(I = 100\;kg\;{m^2}\). Intially the disc is at rest. A \(30\;kg\) boy stands on the edge and begins to walk along the edge at a speed of \(2\;m{s^{ - 1}}\) relative to the ground. Find the angular velocity of the disc.

1 \(2.4\,\,rad/{s^2}\)
2 \(4.8\,\,rad/{s^2}\)
3 \(8\,\,rad/{s^2}\)
4 \(1\,\,rad/{s^2}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365664 A disc of mass \(m_{0}\) rotates freely about a fixed horizontal axis through its center. A thin cotton pad is fixed to its rim, which can absorb water. The mass of water dripping onto the pad is \(\mu\) per second. After what time will the angular velocity of the disc get reduced to half of its initial value:
supporting img

1 \(\dfrac{m_{0}}{\mu}\)
2 \(\dfrac{m_{0}}{2 \mu}\)
3 \(\dfrac{2 m_{0}}{\mu}\)
4 \(\dfrac{3 m_{0}}{\mu}\)
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365665 If the torque of the rotational motion will be zero, then the constant quantity will be

1 angular momentum
2 linear momentum
3 angular acceleration
4 centripetal acceleration
PHXI07:SYSTEMS OF PARTICLES AND ROTATIONAL MOTION

365666 A thin uniform circular disc of mass \(M\) and radius \(\mathrm{R}\) is rotating in a horizontal plane about an axis passing through its centre and perpendicular to the plane with angular velocity \(\omega\). Another disc of same mass but half the radius is gently placed over it coaxially. The angular speed of the composite disc will be :

1 \((5 / 4) \omega\)
2 \((4 / 5) \omega\)
3 \((2 / 5) \omega\)
4 \((5 / 2) \omega\)