A boy standing at the top of a tower of 20 m height drops a stone. Assuming g=, the velocity with which it hits the ground will be:
1. 20 m/s
2. 40 m/s
3. 5 m/s
4. 10 m/s
If a body is thrown up with the velocity of 15 m/s, then the maximum height attained by the body is: (assume g = 10 m/s2)
1. 11.25 m
2. 16.2 m
3. 24.5 m
4. 7.62 m
A body starts to fall freely under gravity. The distances covered by it in first, second and third second will be in the ratio:
1. 1 : 3 : 5
2. 1 : 2 : 3
3. 1 : 4 : 9
4. 1 : 5 : 6
A body is thrown upwards and reaches its maximum height. At that position:
1. | its velocity is zero and its acceleration is also zero. |
2. | its velocity is zero but its acceleration is maximum. |
3. | its acceleration is minimum. |
4. | its velocity is zero and its acceleration is the acceleration due to gravity. |
A stone falls freely under gravity. It covers distances \(h_1,~h_2\) and \(h_3\) in the first \(5\) seconds, the next \(5\) seconds and the next \(5\) seconds respectively. The relation between \(h_1,~h_2\) and \(h_3\) is:
1. | \(h_1=\frac{h_2}{3}=\frac{h_3}{5}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \) |
2. | \(h_2=3h_1\) and \(h_3=3h_2\) |
3. | \(h_1=h_2=h_3\) |
4. | \(h_1=2h_2=3h_3\) |
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 |
A particle is dropped vertically from rest from a height. The time taken by it to fall through successive distances of 1 m each will then be:
1. All equal, being equal to \(\sqrt{2 / g} \) second.
2. In the ratio of the square roots of the integers 1, 2, 3.....
3. In the ratio of the difference in the square roots of the integers \(\sqrt{1}\), \((\sqrt{2}-\sqrt{1})\),\((\sqrt{3}-\sqrt{2})\),\((\sqrt{4}-\sqrt{3})\) \( \ldots\)
4. In the ratio of the reciprocal of the square roots of the integers i.e... \(\frac{1}{\sqrt{1}}\), \(\frac{1}{\sqrt{2}}\), \(\frac{1}{\sqrt{3}}\),\(\frac{1}{\sqrt{4}} \)
A body is thrown vertically up from the ground. It reaches a maximum height of 100 m in 5 seconds. After what time will it reach the ground from the position of maximum height?
1. 1.2 sec
2. 5 sec
3. 10 sec
4. 25 sec
A car travelling at a speed of 30 km/h is brought to rest at a distance of 8 m by applying brakes. If the same car is moving at a speed of 60 km/h, then it can be brought to rest with the same brakes in:
1. 64 m
2. 32 m
3. 16 m
4. 4 m