| 1. | \(\dfrac{3v}{4}\) | 2. | \(\dfrac{v}{3}\) |
| 3. | \(\dfrac{2v}{3}\) | 4. | \(\dfrac{4v}{3}\) |
| 1. | \(\dfrac{1}{v} = \dfrac{1}{v_1}+\dfrac{1}{v_2}\) | 2. | \(\dfrac{2}{v} = \dfrac{1}{v_1}+\dfrac{1}{v_2}\) |
| 3. | \(\dfrac{v}{2} = \dfrac{v_1+v_2}{2}\) | 4. | \(v = \sqrt{v_1v_2}\) |
A particle is moving such that its position coordinates (x, y) are (\(2\) m, \(3\) m) at time \(t=0,\) (\(6\) m,\(7\) m) at time \(t=2\) s, and (\(13\) m, \(14\) m) at time \(t=\) \(5\) s. The average velocity vector \(\vec{v}_{avg}\) from \(t=\) 0 to \(t=\) \(5\) s is:
1. \({1 \over 5} (13 \hat{i} + 14 \hat{j})\)
2. \({7 \over 3} (\hat{i} + \hat{j})\)
3. \(2 (\hat{i} + \hat{j})\)
4. \({11 \over 5} (\hat{i} + \hat{j})\)
Two cars \(P\) and \(Q\) start from a point at the same time in a straight line and their positions are represented by; \(x_p(t)= at+bt^2\) and \(x_Q(t) = ft-t^2. \) At what time do the cars have the same velocity?
| 1. | \(\frac{a-f}{1+b}\) | 2. | \(\frac{a+f}{2(b-1)}\) |
| 3. | \(\frac{a+f}{2(b+1)}\) | 4. | \(\frac{f-a}{2(1+b)}\) |
If the velocity of a particle is \(v=At+Bt^{2},\) where \(A\) and \(B\) are constants, then the distance travelled by it between \(1~\text{s}\) and \(2~\text{s}\) is:
| 1. | \(3A+7B\) | 2. | \(\frac{3}{2}A+\frac{7}{3}B\) |
| 3. | \(\frac{A}{2}+\frac{B}{3}\) | 4. | \(\frac{3A}{2}+4B\) |
| 1. | \(4~\text m\) | 2. | zero |
| 3. | \(6~\text m\) | 4. | \(2~\text m\) |
A body is falling freely in a resistive medium. The motion of the body is described by \(\dfrac{dv}{dt}=(4-2v), \) where \(v\) is the velocity of the body at any instant (in \(\text{ms}^{–1}\)). The terminal velocity in this case refers to the velocity the body approaches as time \(t \to \infty.\) The initial acceleration and terminal velocity of the body, respectively, are:
| 1. | \(4~\text{m/s}^2,\) \(2~\text{m/s}\) | 2. | \(2~\text{m/s}^2,\) \(4~\text{m/s}\) |
| 3. | \(6~\text{m/s}^2,\) \(2~\text{m/s}\) | 4. | \(2~\text{m/s}^2,\) \(6~\text{m/s}\) |
The motion of a particle along a straight line is described by the equation \(x = 8+12t-t^3\) where \(x \) is in meter and \(t\) in seconds. The retardation of the particle, when its velocity becomes zero, is:
| 1. | \(24\) ms-2 | 2. | zero |
| 3. | \(6\) ms-2 | 4. | \(12\) ms-2 |
| 1. | \(5~\text{m}\) | 2. | \(25~\text{m}\) |
| 3. | \(45~\text{m}\) | 4. | \(58~\text{m}\) |