A stone thrown upward with a speed u from the top of the tower reaches the ground with a velocity 3u. The height of the tower is  

1. $3u^2/g$

2. $4u^2/g$

3. $6u^2/g$

4. $9u^2/g$

Two stones of different masses are dropped simultaneously from the top of a building 

1. Smaller stone hit the ground earlier

2. Larger stone hit the ground earlier

3. Both stones reach the ground simultaneously

4. Which of the stones reach the ground earlier depends on the composition of the stone

A body was thrown up with an initial speed of $96ft/\sec$ reaches the ground after: $(g=32ft/{\sec }^2)$ 

1 3 sec

2. 6 sec

3. 12 sec

4. 8 sec

A stone is dropped from a certain height which can reach the ground in \(5\) second. If the stone is stopped after \(3\) second of its fall and then allowed to fall again, then the time taken by the stone to reach the ground for the remaining distance is:
1. \(2~\text{s}\)
2. \(3~\text{s}\)
3. \(4~\text{s}\)
4. None of these

A man in a balloon rising vertically with an acceleration of $4.9m/{\sec }^2$ releases a ball 2 sec after the balloon is let go from the ground. The greatest height above the ground reached by the ball is $(g=9.8m/{\sec }^2)$  

1. 14.7 m

2. 19.6 m

3. 9.8 m

4. 24.5 m

A particle is dropped under gravity from rest from a height $h(g=9.8m/{\sec }^2)$ and it travels a distance 9h/25 in the last second, the height h is

1. 100 m

2. 122.5 m

3. 145 m

4. 167.5 m

Water drops fall at regular intervals from a tap which is 5 m above the ground. The third drop is leaving the tap at the instant the first drop touches the ground. How far above the ground is the second drop at that instant  

1. 2.50 m

2. 3.75 m

3. 4.00 m

4. 1.25 m

A ball is thrown vertically upwards from the top of a tower at $4.9m{s}^{-1}$. It strikes the pond near the base of the tower after 3 seconds. The height of the tower is:

1. 73.5 m

2. 44.1 m

3. 29.4 m

4. None of these

A rocket is fired upward from the earth's surface such that it creates an acceleration of 19.6 m/sec². If after 5 sec its engine is switched off, the maximum height of the rocket from earth's surface would be [MP PET 1995]

1. 245 m

2. 490 m

3. 980 m

4. 735 m

A body starts to fall freely under gravity. The distances covered by it in the first, second and third second will be in the ratio: