A boy standing at the top of a tower of \(20\) m height drops a stone. Assuming \(g=10\) m/s2, 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 the first, second and third second will be in the ratio:
1. | \(1:3:5\) | 2. | \(1:2:3\) |
3. | \(1:4:9\) | 4. | \(1:5:6\) |
1. | \(8\) m | 2. | \(20\) m |
3. | \(10\) m | 4. | \(16\) m |
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 \(g = 10~\text{m/s}^2)\)
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 \(1~\text{m}\) each will then be:
1. | \(\sqrt{2 / g} \) s. | All equal, being equal to
2. | In the ratio of the square roots of the integers \(1,2,3....\) |
3. | \(\sqrt{1}\), \((\sqrt{2}-\sqrt{1})\),\((\sqrt{3}-\sqrt{2})\),\((\sqrt{4}-\sqrt{3})\) \( \ldots\) | In the ratio of the difference in the square roots of the integers
4. | \(\frac{1}{\sqrt{1}}\), \(\frac{1}{\sqrt{2}}\), \(\frac{1}{\sqrt{3}}\),\(\frac{1}{\sqrt{4}} \) | In the ratio of the reciprocal of the square roots of the integers i.e,...
A body is thrown vertically up from the ground. It reaches a maximum height of \(100\) m in \(5\) s. After what time will it reach the ground from the position of maximum height?
1. | \(1.2\) s | 2. | \(5\) s |
3. | \(10\) s | 4. | \(25\) s |
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