| 1. | \(5~ \text m\) | 2. | \(\dfrac{10}{3} \mathrm{~m}\) |
| 3. | \(\dfrac{20}{3} \mathrm{~m}\) | 4. | \(10~ \text m\) |
| 1. | \(2(\hat{i}+\hat{j})\) | 2. | \(\hat{i}+\hat{j}\) |
| 3. | \(\frac{2}{3}(\hat{i}+\hat{j})\) | 4. | \(\frac{4}{3}(\hat{i}+\hat{j})\) |
Which of the following statements are correct?
| (a) | centre of mass of a body always coincides with the centre of gravity of the body . |
| (b) | centre of gravity of a body is the point about which the total gravitational torque on the body is zero. |
| (c) | a couple on a body produce both translational and rotation motion in a body. |
| (d) | mechanical advantage greater than one means that small effort can be used to lift a large load. |
| 1. | (a) and (b) | 2. | (b) and (c) |
| 3. | (c) and (d) | 4. | (b) and (d) |
Two persons of masses \(55~\text{kg}\) and \(65~\text{kg}\) respectively, are at the opposite ends of a boat. The length of the boat is \(3.0~\text{m}\) and weighs \(100~\text{kg}.\) The \(55~\text{kg}\) man walks up to the \(65~\text{kg}\) man and sits with him. If the boat is in still water, the centre of mass of the system shifts by:
1. \(3.0~\text{m}\)
2. \(2.3~\text{m}\)
3. zero
4. \(0.75~\text{m}\)
| 1. | \(\dfrac{\omega_1}{x_1}=\dfrac{\omega_2}{x_2}=\dfrac{\omega_3}{x_3}={k}\) |
| 2. | \(\omega_{1}x_{1}=\omega_{2}x_{2}=\omega_{3}x_{3}={k}\) |
| 3. | \(\omega_{1}x_{1}^{2}=\omega_{2}x_{2}^{2}=\omega_{3}x_{3}^{2}={k}\) |
| 4. | \(\omega_{1}^{2}x_{1}=\omega_{2}^{2}x_{2}=\omega_{3}^{2}x_{3}={k}\) |
| 1. | along the axis of rotation |
| 2. | along the radius, away from the centre |
| 3. | along the radius towards the centre |
| 4. | along the tangent to its position |
| 1. | \( \dfrac{v_0}{n} ~\text{rad} / \text{s}^2\) | 2. | \( \dfrac{v_0^2}{2 \pi {nr}^2}~ \text{rad} / \text{s}^2 \) |
| 3. | \( \dfrac{v_0^2}{4 \pi {n}{r}^2}~ \text{rad} / \text{s}^2 \) | 4. | \( \dfrac{v_0^2}{4 \pi {nr}} ~\text{rad} / \text{s}^2 \) |
| 1. | \(\dfrac{7}{57}\) | 2. | \(\dfrac{7}{64}\) |
| 3. | \(\dfrac{7}{8}\) | 4. | \(\dfrac{7}{40}\) |
| 1. | \(5\) | 2. | \(\sqrt{2}\) |
| 3. | \(\sqrt{3}\) | 4. | \(\sqrt{5}\) |