A stone is thrown vertically downwards with an initial velocity of \(40\) m/s from the top of a building. If it reaches the ground with a velocity of \(60\) m/s, then the height of the building is: (Take \(g=10\) m/s2)
1. \(120\) m
2. \(140\) m
3. \(80\) m
4. \(100\) m
The figure given below shows the displacement and time, \((x\text -t)\) graph of a particle moving along a straight line:
The correct statement, about the motion of the particle, is:
1. | the particle moves at a constant velocity up to a time \(t_0\) and then stops. |
2. | the particle is accelerated throughout its motion. |
3. | the particle is accelerated continuously for time \(t_0\) then moves with constant velocity. |
4. | the particle is at rest. |
1. | 2. | ||
3. | 4. |
1. | \(1: \sqrt{3}\) | 2. | \(\sqrt{3}: 1\) |
3. | \(1:1\) | 4. | \(1:2\) |
A small block slides down on a smooth inclined plane starting from rest at time \(t=0.\) Let \(S_n\) be the distance traveled by the block in the interval \(t=n-1\) to \(t=n.\) Then the ratio \(\frac{S_n}{S_{n +1}}\) is:
1. \(\frac{2n+1}{2n-1}\)
2. \(\frac{2n}{2n-1}\)
3. \(\frac{2n-1}{2n}\)
4. \(\frac{2n-1}{2n+1}\)
A man throws some balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time? (Given g = 9.8 m/s2)
1. More than 19.6 m/s
2. At least 9.8 m/s
3. Any speed less than 19.6 m/s
4. Only with a speed of 19.6 m/s
If a ball is thrown vertically upwards with speed u, the distance covered during the last ‘t’ seconds of its ascent is:
1. ut
2.
3.
4.