A car moving along a straight highway with a speed of \(126\) km/h is brought to a stop within a distance of \(200\) m. How long does it take for the car to stop?
1. \(10.2\) s
2. \(9.6\) s
3. \(11.4\) s
4. \(6.7\) s
The figure gives the \((x\text-t)\) plot of a particle in a one-dimensional motion. Three different equal intervals of time are shown. The signs of average velocity for each of the intervals \(1,\) \(2\) & \(3,\) respectively are:
1. | \(-,-,+\) |
2. | \(+,-,+\) |
3. | \(-,+,+\) |
4. | \(+,+,-\) |
The figure gives a speed-time graph of a particle in motion along the same direction. Three equal intervals of time are shown. In which interval is the average acceleration greatest in magnitude?
1. | Interval 2
|
2. | Interval 1
|
3. | Interval 3
|
4. | Equal in all intervals |
A boy standing on a stationary lift (open from above) throws a ball upwards with the maximum initial speed he can, equal to How much time does the ball take to return to his hands?
1. 5 s
2. 10 s
3. 15 s
4. 7 s
A passenger arriving in a new town wishes to go from the station to a hotel located 10 km away on a straight road from the station. A dishonest cabman takes him along a circuitous path 23 km long and reaches the hotel in 28 min. The average speed of the taxi is:
1. 30 km/h
2. 49.3 km/h
3. 55.6 km/h
4. 60 km/h
A car moves with a speed of \(60\) km/h for \(1\) hour in the east direction and with the same speed for \(30\) min in the south direction. The displacement of the car from the initial position is:
1. \(60\) km
2. \(30 \sqrt{2}\) km
3. \(30 \sqrt{5}\) km
4. \(60 \sqrt{2}\) km
A body in one-dimensional motion has zero speed at an instant. At that instant, it must have:
1. | zero velocity. | 2. | zero acceleration. |
3. | non-zero velocity. | 4. | non-zero acceleration. |
If a particle is moving along a straight line with increasing speed, then:
1. | its acceleration is negative. |
2. | its acceleration may be decreasing. |
3. | its acceleration is positive. |
4. | both (2) & (3) |
When the velocity of a body is variable, then:
1. | its speed may be constant |
2. | its acceleration may be constant |
3. | its average acceleration may be constant |
4. | all of the above |
A particle moves with velocity v1 for time t1 and v2 for time t2 along a straight line. The magnitude of its average acceleration is:
1.
2.
3.
4.