In the figure, the coefficient of friction between the floor and body \(B\) is \(0.1.\) The coefficient of friction between bodies \(B\) and \(A\) is \(0.2.\) A force \(F\) is applied as shown on \(B.\) The mass of \(A\) is \(rn/2\) and of \(B\) is \(m.\)
(a) | The bodies will move together if \(F = 0.25~\text{mg}\) |
(b) | The \(A\) will slip with \(B\) if \(F = 0.5~\text{mg}\) |
(c) | The bodies will move together if \(F = 0.5~\text{mg}\) |
(d) | The bodies will be at rest if \(F = 0.1~\text{mg}\) |
(e) | The maximum value of \(F\) for which the two bodies will move together is \(0.45~\text{mg}\) |
Which of the following statement(s) is/are true?
1. | (a, b, d, e) | 2. | (a, c, d, e) |
3. | (b, c, d) | 4. | (a, b, c) |
The figure shows the position-time graph of a particle of mass \(4\) kg. What is the force on the particle for \(t>4\) s? (Consider one-dimensional motion only).
1. \(0\)
2. \(40~\mathrm{N}\)
3. \(20~\mathrm{N}\)
4. \(10~\mathrm{N}\)
Assertion (A): | A man who falls from a height on a cement floor receives more injury than when he falls from the same height on a heap of sand. |
Reason (R): | The impulse applied by a cement floor is less than the impulse applied by a sand floor. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | A rocket moves forward by pushing the surrounding air backward. |
Reason (R): | It derives the necessary thrust to move forward according to Newton's first law of motion. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | A rocket works on the principle of conservation of linear momentum. |
Reason (R): | Higher is the velocity, smaller is the pressure and vice-versa. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The driver in a vehicle moving at a constant speed on a straight road is in a non-inertial frame of reference. |
Reason (R): | A reference frame in which Newton's law of motion is applicable is non-inertial. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | A man in a closed cabin, which is falling freely, does not experience gravity. |
Reason (R): | Inertial and gravitational mass have equivalence. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Assertion (A): | The principle of rocket propulsion is a special case of a variable mass system. |
Reason (R): | The principle of rocket propulsion can be explained by Newton's second law. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |