A particle is moving such that its position coordinates \((x,y)\) are \( (2~\text m, 3~\text m)\) at time \(t=0,\) \( (6~\text m, 7~\text m)\) at time \(t=2~\text s\) and \( (13~\text m, 14~\text m)\) at time \(t=5~\text s.\) The average velocity vector \((v_{avg})\) from \(t=0\) to \(t=5~\text s\) is:
1. | \(\frac{1}{5}\left ( 13\hat{i}+14\hat{j} \right )\) | 2. | \(\frac{7}{3}\left ( \hat{i}+\hat{j} \right )\) |
3. | \(2\left ( \hat{i}+\hat{j} \right )\) | 4. | \(\frac{11}{5}\left ( \hat{i}+\hat{j} \right )\) |
A car turns at a constant speed on a circular track of radius \(100~\text m,\) taking \(62.8~\text s\) for every circular lap. The average velocity and average speed for each circular lap, respectively, is:
1. | \(0,~0\) | 2. | \(0,\) \(10~\text{m/s},\) |
3. | \(10~\text{m/s},\) \(10~\text{m/s},\) | 4. | \(10~\text{m/s},\) \(0\) |
The coordinates of a moving particle at any time \(t\) are given by \(x= \alpha t^3\) and \(y = \beta t^3.\) The speed of the particle at a time \(t\) is given by:
1. | \(\sqrt{\alpha^{2} + \beta^{2}}\) | 2. | \(3t \sqrt{\alpha^{2} + \beta^{2}}\) |
3. | \(3t^{2} \sqrt{\alpha^{2} +\beta^{2}}\) | 4. | \(t^{2} \sqrt{\alpha^{2} +\beta^{2}}\) |
Two particles \(A\) and \(B,\) move with constant velocities \(\vec{v_1}\) and \(\vec{v_2}.\) At the initial moment their position vector are \(\vec {r_1}\) and \(\vec {r_2}\) respectively. The conditions for particles \(A\) and \(B\) for their collision to happen will be:
1. | \(\vec{r_{1 }} . \vec{v_{1}} = \vec{r_{2 }} . \vec{v_{2}}\) | 2. | \(\vec{r_{1}} \times\vec{v_{1}} = \vec{r_{2}} \times \vec {v_{2}}\) |
3. | \(\vec{r_{1}}-\vec{r_{2}}=\vec{v_{1}} - \vec{v_{2}}\) | 4. | \(\frac{\vec{r_{1}} - \vec{r_{2}}}{\left|\vec{r_{1}} - \vec{r_{2}}\right|} = \frac{\vec{v_{2}} - \vec{v_{1}}}{\left|\vec{v_{2}} - \vec{v_{1}}\right|}\) |
Two particles move from \(A\) to \(C\) and \(A\) to \(D\) on a circle of radius \(R\) and the diameter \(AB.\) If the time taken by both particles is the same, then the ratio of magnitudes of their average velocities is:
1. \(2\)
2. \(2\sqrt{3}\)
3. \(\sqrt{3}\)
4. \(\dfrac{\sqrt{3}}{2}\)
A bus is going to the North at a speed of \(30\) kmph. It makes a \(90^{\circ}\) left turn without changing the speed. The change in the velocity of the bus is:
1. | \(30~\text{kmph}\) towards \(\mathrm{W}\) |
2. | \(30~\text{kmph}\) towards \(\mathrm{S\text-W}\) |
3. | \(42.4~\text{kmph}\) towards \(\mathrm{S\text-W}\) |
4. | \(42.4~\text{kmph}\) towards \(\mathrm{N\text-W}\) |
Three particles are moving with constant velocities \(v_1 ,v_2\) and \(v\) respectively as given in the figure. After some time, if all the three particles are in the same line, then the relation among \(v_1 ,v_2\) and \(v\) is:
1. \(v =v_1+v_2\)
2. \(v= \sqrt{v_{1} v_{2}}\)
3. \(v = \frac{v_{1} v_{2}}{v_{1} + v_{2}}\)
4. \(v=\frac{\sqrt{2} v_{1} v_{2}}{v_{1} + v_{2}}\)