Physics #restart (Motion in A Straight Line SET C - Medium)Contact Number: 8527521718Physics #restart (Motion in A Straight Line SET C - Medium)Contact Number: 8527521718A drunkard walking in a narrow lane takes \(5\) steps forward and \(3\) steps backward, followed again by \(5\) steps forward and \(3\) steps backward, and so on. Each step is \(1\) m long and requires \(1\) s. There is a pit on the road \(13\) m away from the starting point. The drunkard will fall into the pit after:
1. \(37\) s
2. \(31\) s
3. \(29\) s
4. \(33\) s
A particle moves with a velocity \(v = αt^{3}\) along a straight line. The average speed in time interval \(t=0\) to \(t=T\) will be:
1. \(\alpha T^3\)
2. \(\frac{αT^{3}}{2}\)
3. \(\frac{\alpha T^3}{3}\)
4. \(\frac{αT^{3}}{4}\)
Which of the following four statements is false?
| 1. | A body can have zero velocity and still be accelerated. |
| 2. | A body can have a constant velocity and still have a varying speed. |
| 3. | A body can have a constant speed and still have a varying velocity. |
| 4. | The direction of the velocity of a body can change when its acceleration is constant. |
A particle moves a distance \(x\) in time \(t\) according to equation \(x = (t+5)^{-1}\). The acceleration of the particle is proportional to:
| 1. | \((\text{velocity})^{\frac{3}{2}}\) | 2. | \((\text{distance})^2\) |
| 3. | \((\text{distance})^{-2}\) | 4. | \((\text{velocity})^{\frac{2}{3}}\) |
A person sitting on the ground floor of a building notices through the window, of height \(1.5~\text{m}\), a ball dropped from the roof of the building crosses the window in \(0.1~\text{s}\). What is the velocity of the ball when it is at the topmost point of the window? \(\left(g = 10~\text{m/s}^2\right )\)
| 1. | \(15.5~\text{m/s}\) | 2. | \(14.5~\text{m/s}\) |
| 3. | \(4.5~\text{m/s}\) | 4. | \(20~\text{m/s}\) |
The position-time \((x\text-t)\) graphs for two children \(A\) and \(B\) returning from their school \(O\) to their homes \(P\) and \(Q\) respectively are shown in the graph.
Choose the incorrect statement:
| 1. | \(B\) reaches home faster than \(A.\) |
| 2. | \(B\) overtakes \(A\) on the road twice. |
| 3. | \(B\) walks faster than \(A.\) |
| 4. | \(A\) lives closer to the school than \(B.\) |
Acceleration-time graph of a body is shown.
The corresponding velocity-time graph of the same body is:
| 1. |  |
2. |  |
| 3. |  |
4. |  |
An elevator whose floor-to-ceiling height is \(12\) meters, moves upward with an acceleration of \(2.2~\text{m/s}^2.\) After \(1.5~\text s\) since starting, a bolt falls from its ceiling. The time taken by the bolt to reach the floor is:
1. \(1~\text{s}\)
2. \(2~\text{s}\)
3. \(\sqrt{2}~\text{s}\)
4. \(\sqrt{3}~\text{s}\)
A helicopter moving vertically upwards releases a packet when it is at a certain height above the ground. The packet initially moves upwards for a time \(t_1\) and then falls downwards for a time \(t_2\) until it reaches the ground. Then:
| 1. | \(t_1<t_2\) | 2. | \(t_1=t_2\) |
| 3. | \(t_1>t_2\) | 4. | Data insufficient |
| Assertion (A): | A body can have acceleration even if its velocity is zero at a given instant of time. |
| Reason (R): | A body is momentarily at rest when it reverses its direction 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. |
