Assertion (A): | If two particles move with uniform accelerations in different directions, then their relative velocity changes in direction. |
Reason (R): | Since the acceleration are in different directions, there is a relative acceleration and hence the relative velocity changes. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
A man drifting on a raft on a river observes a boat moving in the same direction at a relative speed which is \(3\) times the speed of the river's flow of \(3\) km/h. The boat overtakes him at a certain moment and reaches a point downstream after a time \(T_B\) while he reaches the same point after \(T_A=3 \) hr. Then, \(T_B= \)
1. | \(1\) hr | 2. | \(\dfrac12\)hr |
3. | \(\dfrac23\) hr | 4. | \(\dfrac34\) hr |
1. | \(v_A~\text{cos}A=v_B~\text{cos}B\) |
2. | \(v_A~\text{sin}A=v_B~\text{sin}B\) |
3. | \(\dfrac{v_A}{\text{sin}A}=\dfrac{v_B}{\text{sin}B}\) |
4. | \(v_A~\text{tan}A=v_B~\text{tan}B\) |
1. | \(u_1=\dfrac{\sqrt3}{2}u_2\) | 2. | \(u_1=\dfrac{1}{2}u_2\) |
3. | \(u_1=\dfrac{1}{\sqrt2}u_2\) | 4. | \(u_1=\dfrac{1}{\sqrt3}u_2\) |
1. | \(2.4~\text{km/h}\) | 2. | \(4.8~\text{km/h}\) |
3. | \(2.4\sqrt2~\text{km/h}\) | 4. | \(\dfrac{2.4}{\sqrt2}~\text{km/h}\) |
1. | \(10\) min | 2. | \(5\sqrt3\) min |
3. | \(20\) min | 4. | \(\dfrac{10}{\sqrt3}\) min |
1. | \(2\) m/s | 2. | \(4\) m/s |
3. | \(2\sqrt3 \) m/s | 4. | \(4\sqrt3 \) m/s |
Assertion (A): | If the velocities of two particles are perpendicular to each other, then their separation must be increasing with time. |
Reason (R): | The relative velocity between the two particles is higher in magnitude than either of them. |
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. | (A) is False but (R) is True. |