
| 1. | \(80\) m due south | 2. | \(80\) m due east |
| 3. | \(30\) m due south | 4. | \(30\) m due east |
A particle starts from the origin at time \(t=0 \) with an initial velocity of \(5\hat{j}~\text{ms}^{-1}. \) It moves in the \(XY \text-\)plane under a constant acceleration of \(\left(10\hat{i}+4\hat{j}\right)~\text{ms}^{-2} .\) At some later time \(t,\) the coordinates of the particle are \((20~\text{m}, y_0~\text{m}). \) The values of \(t \) and \(y_0 \) are, respectively:
1. \(4~\text{s}\) and \(52~\text{m}\)
2. \(5~\text{s}\) and \(25~\text{m}\)
3. \(2~\text{s}\) and \(18~\text{m}\)
4. \(2~\text{s}\) and \(24~\text{m}\)
The position vector of a moving particle at time t is . Its displacement during the time interval, t = 1 s to t = 3 s is :
1.
2.
3.
4.
| 1. | \(5.0\) km | 2. | \(21.0\) km |
| 3. | \(10.0\) km | 4. | \(7.0\) km |
| 1. | \(2 × 10^4\) km | 2. | \(\big(\frac\pi2\big)\times10^4\) km |
| 3. | \(\sqrt2\times10^4\) km | 4. | \(\pi\times10^4\) km |
The position of a particle at time \(t\) is given by, \(x=3t^3\), \(y=2t^2+8t\), and \(z=6t-5\). The initial velocity of the particle is:
| 1. | \(20\) unit | 2. | \(10\) unit |
| 3. | \(5\) unit | 4. | \(13\) unit |