A ball is thrown vertically downwards with a velocity of \(20\) m/s from the top of a tower. It hits the ground after some time with the velocity of \(80\) m/s . The height of the tower is: (assuming
1. | \(340\) m | 2. | \(320\) m |
3. | \(300\) m | 4. | \(360\) m |
If a particle has negative velocity and negative acceleration, its speed:
1. | increases |
2. | decreases |
3. | remains the same |
4. | zero |
A particle starts from rest (with constant acceleration) and acquires velocity 20 m/s in 5s. The distance travelled by the particle in the next 2 s will be:
1. | 50 m | 2. | 48 m |
3. | 100 m | 4. | 150 m |
A 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
The position-time \((x-t)\) 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 \(B.\) |
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