QBManager

Rotational Motion

269281 Two balls are thrown at the same time in air, while they are in air, the acceleration of their centre of mass

1 depends on masses of the balls

2 depends on the direction of motion of the balls

3 depends on speeds of the balls

4 is equal to acceleration due to gravity

Rotational Motion

269282 Consider a two particle system with the particles having masses $m_{1}$ and $m_{2}$ . If the first particle is pushed towards the centre of mass through a distance $d$ , by what distance should the second particle be moved, so as to keep the centre of mass at the same position? [MAINS 2006]

1

d

2

\frac{m_{2} d}{m_{1}}

3

\frac{m_{1} d}{m_{1} + m_{2}}

4

\frac{m_{1} d}{m_{2}}

Rotational Motion

269365 Two bodies of different masses $2 kg$ and $4 kg$ are moving with velocities $2 m / s$ and $10 m / s$ towards each other due to mutual gravitational attraction. Then the velocity of the centre of mass is

1

5 {ms}^{- 1}

2

6 {ms}^{- 1}

3

8 {ms}^{- 1}

4 Zero

Explanation:

$v_{c m} = \frac{m_{1} v_{1} + m_{2} v_{2}}{m_{1} + m_{2}}$ ; Internal force does not change the position of centre of mass

Rotational Motion

269366 If two particles of masses $3 kg$ and $6 kg$ which are at rest are separated by a distance of $15 m$ . The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is

1

2 : 1

2

1 : 2

3

1 : 3

4

3 : 1

Explanation:

$m_{1} r_{1} = m_{2} r_{2}$

Rotational Motion

269367 Two bodies of $6 k g$ and $4 k g m a s s e s h a v e t h e i r$ velocity $5 \hat{i} - 2 \hat{j} + 10 \hat{k}$ and $10 \hat{i} - 2 \hat{j} + 5 \hat{k}$ respectively.Then the velocity of their centre of mass is

1

5 \hat{i} + 2 \hat{j} - 8 \hat{k}

2

7 \hat{i} + 2 \hat{j} - 8 \hat{k}

3

7 \hat{i} - 2 \hat{j} + 8 \hat{k}

4

5 \hat{i} - 2 \hat{j} + 8 \hat{k}

Explanation:

${\vec{v}}_{c m} = \frac{m_{1} {\vec{v}}_{1} + m_{2} {\vec{v}}_{2}}{m_{1} + m_{2}}$

Rotational Motion

269281 Two balls are thrown at the same time in air, while they are in air, the acceleration of their centre of mass

1 depends on masses of the balls

2 depends on the direction of motion of the balls

3 depends on speeds of the balls

4 is equal to acceleration due to gravity

Rotational Motion

269282 Consider a two particle system with the particles having masses $m_{1}$ and $m_{2}$ . If the first particle is pushed towards the centre of mass through a distance $d$ , by what distance should the second particle be moved, so as to keep the centre of mass at the same position? [MAINS 2006]

1

d

2

\frac{m_{2} d}{m_{1}}

3

\frac{m_{1} d}{m_{1} + m_{2}}

4

\frac{m_{1} d}{m_{2}}

Rotational Motion

269365 Two bodies of different masses $2 kg$ and $4 kg$ are moving with velocities $2 m / s$ and $10 m / s$ towards each other due to mutual gravitational attraction. Then the velocity of the centre of mass is

1

5 {ms}^{- 1}

2

6 {ms}^{- 1}

3

8 {ms}^{- 1}

4 Zero

Explanation:

$v_{c m} = \frac{m_{1} v_{1} + m_{2} v_{2}}{m_{1} + m_{2}}$ ; Internal force does not change the position of centre of mass

Rotational Motion

269366 If two particles of masses $3 kg$ and $6 kg$ which are at rest are separated by a distance of $15 m$ . The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is

1

2 : 1

2

1 : 2

3

1 : 3

4

3 : 1

Explanation:

$m_{1} r_{1} = m_{2} r_{2}$

Rotational Motion

269367 Two bodies of $6 k g$ and $4 k g m a s s e s h a v e t h e i r$ velocity $5 \hat{i} - 2 \hat{j} + 10 \hat{k}$ and $10 \hat{i} - 2 \hat{j} + 5 \hat{k}$ respectively.Then the velocity of their centre of mass is

1

5 \hat{i} + 2 \hat{j} - 8 \hat{k}

2

7 \hat{i} + 2 \hat{j} - 8 \hat{k}

3

7 \hat{i} - 2 \hat{j} + 8 \hat{k}

4

5 \hat{i} - 2 \hat{j} + 8 \hat{k}

Explanation:

${\vec{v}}_{c m} = \frac{m_{1} {\vec{v}}_{1} + m_{2} {\vec{v}}_{2}}{m_{1} + m_{2}}$

Rotational Motion

269281 Two balls are thrown at the same time in air, while they are in air, the acceleration of their centre of mass

1 depends on masses of the balls

2 depends on the direction of motion of the balls

3 depends on speeds of the balls

4 is equal to acceleration due to gravity

Rotational Motion

269282 Consider a two particle system with the particles having masses $m_{1}$ and $m_{2}$ . If the first particle is pushed towards the centre of mass through a distance $d$ , by what distance should the second particle be moved, so as to keep the centre of mass at the same position? [MAINS 2006]

1

d

2

\frac{m_{2} d}{m_{1}}

3

\frac{m_{1} d}{m_{1} + m_{2}}

4

\frac{m_{1} d}{m_{2}}

Rotational Motion

269365 Two bodies of different masses $2 kg$ and $4 kg$ are moving with velocities $2 m / s$ and $10 m / s$ towards each other due to mutual gravitational attraction. Then the velocity of the centre of mass is

1

5 {ms}^{- 1}

2

6 {ms}^{- 1}

3

8 {ms}^{- 1}

4 Zero

Explanation:

$v_{c m} = \frac{m_{1} v_{1} + m_{2} v_{2}}{m_{1} + m_{2}}$ ; Internal force does not change the position of centre of mass

Rotational Motion

269366 If two particles of masses $3 kg$ and $6 kg$ which are at rest are separated by a distance of $15 m$ . The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is

1

2 : 1

2

1 : 2

3

1 : 3

4

3 : 1

Explanation:

$m_{1} r_{1} = m_{2} r_{2}$

Rotational Motion

269367 Two bodies of $6 k g$ and $4 k g m a s s e s h a v e t h e i r$ velocity $5 \hat{i} - 2 \hat{j} + 10 \hat{k}$ and $10 \hat{i} - 2 \hat{j} + 5 \hat{k}$ respectively.Then the velocity of their centre of mass is

1

5 \hat{i} + 2 \hat{j} - 8 \hat{k}

2

7 \hat{i} + 2 \hat{j} - 8 \hat{k}

3

7 \hat{i} - 2 \hat{j} + 8 \hat{k}

4

5 \hat{i} - 2 \hat{j} + 8 \hat{k}

Explanation:

${\vec{v}}_{c m} = \frac{m_{1} {\vec{v}}_{1} + m_{2} {\vec{v}}_{2}}{m_{1} + m_{2}}$

Rotational Motion

269281 Two balls are thrown at the same time in air, while they are in air, the acceleration of their centre of mass

1 depends on masses of the balls

2 depends on the direction of motion of the balls

3 depends on speeds of the balls

4 is equal to acceleration due to gravity

Rotational Motion

269282 Consider a two particle system with the particles having masses $m_{1}$ and $m_{2}$ . If the first particle is pushed towards the centre of mass through a distance $d$ , by what distance should the second particle be moved, so as to keep the centre of mass at the same position? [MAINS 2006]

1

d

2

\frac{m_{2} d}{m_{1}}

3

\frac{m_{1} d}{m_{1} + m_{2}}

4

\frac{m_{1} d}{m_{2}}

Rotational Motion

269365 Two bodies of different masses $2 kg$ and $4 kg$ are moving with velocities $2 m / s$ and $10 m / s$ towards each other due to mutual gravitational attraction. Then the velocity of the centre of mass is

1

5 {ms}^{- 1}

2

6 {ms}^{- 1}

3

8 {ms}^{- 1}

4 Zero

Explanation:

$v_{c m} = \frac{m_{1} v_{1} + m_{2} v_{2}}{m_{1} + m_{2}}$ ; Internal force does not change the position of centre of mass

Rotational Motion

269366 If two particles of masses $3 kg$ and $6 kg$ which are at rest are separated by a distance of $15 m$ . The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is

1

2 : 1

2

1 : 2

3

1 : 3

4

3 : 1

Explanation:

$m_{1} r_{1} = m_{2} r_{2}$

Rotational Motion

269367 Two bodies of $6 k g$ and $4 k g m a s s e s h a v e t h e i r$ velocity $5 \hat{i} - 2 \hat{j} + 10 \hat{k}$ and $10 \hat{i} - 2 \hat{j} + 5 \hat{k}$ respectively.Then the velocity of their centre of mass is

1

5 \hat{i} + 2 \hat{j} - 8 \hat{k}

2

7 \hat{i} + 2 \hat{j} - 8 \hat{k}

3

7 \hat{i} - 2 \hat{j} + 8 \hat{k}

4

5 \hat{i} - 2 \hat{j} + 8 \hat{k}

Explanation:

${\vec{v}}_{c m} = \frac{m_{1} {\vec{v}}_{1} + m_{2} {\vec{v}}_{2}}{m_{1} + m_{2}}$

Rotational Motion

269281 Two balls are thrown at the same time in air, while they are in air, the acceleration of their centre of mass

1 depends on masses of the balls

2 depends on the direction of motion of the balls

3 depends on speeds of the balls

4 is equal to acceleration due to gravity

Rotational Motion

269282 Consider a two particle system with the particles having masses $m_{1}$ and $m_{2}$ . If the first particle is pushed towards the centre of mass through a distance $d$ , by what distance should the second particle be moved, so as to keep the centre of mass at the same position? [MAINS 2006]

1

d

2

\frac{m_{2} d}{m_{1}}

3

\frac{m_{1} d}{m_{1} + m_{2}}

4

\frac{m_{1} d}{m_{2}}

Rotational Motion

269365 Two bodies of different masses $2 kg$ and $4 kg$ are moving with velocities $2 m / s$ and $10 m / s$ towards each other due to mutual gravitational attraction. Then the velocity of the centre of mass is

1

5 {ms}^{- 1}

2

6 {ms}^{- 1}

3

8 {ms}^{- 1}

4 Zero

Explanation:

$v_{c m} = \frac{m_{1} v_{1} + m_{2} v_{2}}{m_{1} + m_{2}}$ ; Internal force does not change the position of centre of mass

Rotational Motion

269366 If two particles of masses $3 kg$ and $6 kg$ which are at rest are separated by a distance of $15 m$ . The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is

1

2 : 1

2

1 : 2

3

1 : 3

4

3 : 1

Explanation:

$m_{1} r_{1} = m_{2} r_{2}$

Rotational Motion

269367 Two bodies of $6 k g$ and $4 k g m a s s e s h a v e t h e i r$ velocity $5 \hat{i} - 2 \hat{j} + 10 \hat{k}$ and $10 \hat{i} - 2 \hat{j} + 5 \hat{k}$ respectively.Then the velocity of their centre of mass is

1

5 \hat{i} + 2 \hat{j} - 8 \hat{k}

2

7 \hat{i} + 2 \hat{j} - 8 \hat{k}

3

7 \hat{i} - 2 \hat{j} + 8 \hat{k}

4

5 \hat{i} - 2 \hat{j} + 8 \hat{k}

Explanation:

${\vec{v}}_{c m} = \frac{m_{1} {\vec{v}}_{1} + m_{2} {\vec{v}}_{2}}{m_{1} + m_{2}}$