A bullet moving at speed of \(10\text{ m/s}\) hits the wooden plank and is stopped when it penetrates the plank \(50\text{ cm}\) deep. What is the retardation of bullet? (Assuming constant retardation)
1. \(100\text{ m/s}^2\)
2. \(1000\text{ m/s}^2\)
3. \(50\text{ m/s}^2\)
4. \(250\text{ m/s}^2\)
A particle has initial velocity \(\left(2 \hat{i} + 3 \hat{j}\right)\) and acceleration \(\left(0 . 3 \hat{i} + 0 . 2 \hat{j}\right)\). The magnitude of velocity after \(10\) s will be:
| 1. | \(9 \sqrt{2}~ \text{units}\) | 2. | \(5 \sqrt{2} ~\text{ units}\) |
| 3. | \(5~\text{units}\) | 4. | \(9~\text{units}\) |
| 1. | distance travelled | 2. | time travelled |
| 3. | average velocity | 4. | average speed |
| 1. | \(25\) s | 2. | \(20\) s |
| 3. | \(30\) s | 4. | \(15\) s |
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 |
A particle starts from origin \(O\) from rest and moves with a uniform acceleration along the positive \(x\text-\)axis. Identify all figures that correctly represent the motion qualitatively.
(\(a=\) acceleration, \(v=\) velocity, \(x=\) displacement, \(t=\) time)
| (A) | (B) | ||
| (C) | (D) |
| 1. | (A) only |
| 2. | (A), (B) and (D) only |
| 3. | (B) and (C) only |
| 4. | (A), (B) and (C) only |
| 1. | \(50~\text{m}\) | 2. | \(5~\text{m}\) |
| 3. | \(25~\text{m}\) | 4. | \(64.8~\text{m}\) |