Q. No.
| 1. | \(1.4\) m | 2. | \(1.0\) m |
| 3. | \(0.8\) m | 4. | \(0.6\) m |
Rain is falling vertically downward with a speed of \(35~\text{m/s}.\) The wind starts blowing after some time with a speed of \(12~\text{m/s}\) in the east to the west direction. The direction in which a boy standing at the place should hold his umbrella is:
| 1. | \(\text{tan}^{-1}\Big(\frac{12}{37}\Big)\) with respect to rain |
| 2. | \(\text{tan}^{-1}\Big(\frac{12}{37}\Big)\) with respect to wind |
| 3. | \(\text{tan}^{-1}\Big(\frac{12}{35}\Big)\) with respect to rain |
| 4. | \(\text{tan}^{-1}\Big(\frac{12}{35}\Big)\) with respect to wind |
A particle starting from the point \((1,2)\) moves in a straight line in the XY-plane. Its coordinates at a later time are \((2,3).\) The path of the particle makes with \(x\)-axis an angle of:
| 1. | \(30^\circ\) | 2. | \(45^\circ\) |
| 3. | \(60^\circ\) | 4. | data is insufficient |
| 1. | \(10\) min | 2. | \(5\sqrt3\) min |
| 3. | \(20\) min | 4. | \(\dfrac{10}{\sqrt3}\) min |
A motorboat is racing towards the north at \(25\) km/h and the water current in that region is \(10\) km/h in the direction of \(60^\circ\) east of the south. The resultant velocity of the boat is:
| 1. | \(12\) km/h at \(23 . 4^\circ\) east of west |
| 2. | \(22\) km/h at \(23 . 4^\circ\) north of east |
| 3. | \(22\) km/h at \(23 . 4^\circ\) east of north |
| 4. | \(20\) km/h at \(23 . 4^\circ\) north of west |
| 1. | \(4\sqrt2~\text{ms}^{-1},45^\circ\) | 2. | \(4\sqrt2~\text{ms}^{-1},60^\circ\) |
| 3. | \(3\sqrt2~\text{ms}^{-1},30^\circ\) | 4. | \(3\sqrt2~\text{ms}^{-1},45^\circ\) |
The position of a particle is given by,
\(\overrightarrow{\text{r}}=(3.0 \text{t} \hat{\text{i}}-2.0 \text{t}^2 \hat{\text{j}}+4.0 \hat{\text{k}} )~\text{m}\)
where \(t\) is in seconds and the coefficients have the proper units for \(\vec{r}\) to be in meters. What is the magnitude and direction of the velocity of the particle at \(t=2.0\) s?
1. \(7.56~ \text{m} \text{s}^{-1},-70^{\circ}\text{ with} ~\text{y} \text{-axis}. \)
2. \(7.56~ \text{m} \text{s}^{-1}, ~70^{\circ}\text{ with} ~\text{x} \text{-axis}. \)
3. \(8.54 ~\text{m} \text{s}^{-1},~70^{\circ}\text{ with} ~\text{y} \text{-axis}. \)
4. \(8.54 ~\text{m} \text{s}^{-1},-70^{\circ}\text{ with} ~\text{x} \text{-axis}. \)
In a two-dimensional motion, instantaneous speed \(v_0\) is a positive constant. Then which of the following is necessarily true?
| 1. | The acceleration of the particle is zero. |
| 2. | The acceleration of the particle is increasing. |
| 3. | The acceleration of the particle is necessarily in the plane of motion. |
| 4. | The particle must be undergoing a uniform circular motion. |
The following are four different relations about displacement, velocity and acceleration for the motion of a particle in general.
| (a) | \(v_{a v}=1 / 2\left[v\left(t_1\right)+v\left(t_2\right)\right]\) |
| (b) | \(v_{{av}}={r}\left({t}_2\right)-{r}\left({t}_1\right) / {t}_2-{t}_1\) |
| (c) | \(r=1 / 2\left[v\left(t_2\right)-v\left(t_1\right)\right]\left({t}_2-{t}_1\right)\) |
| (d) | \({a}_{{av}}=v\left({t}_2\right)-v\left({t}_1\right) / {t}_2-{t}_1\) |
The incorrect alternative/s is/are:
| 1. | (a), (d) | 2. | (a), (c) |
| 3. | (b), (c) | 4. | (a), (b) |
In a two-dimensional motion, instantaneous speed \(v_0\) is a positive constant. Then which of the following is necessarily true?
| 1. | the average velocity is not zero at any time. |
| 2. | average acceleration must always vanish. |
| 3. | displacements in equal time intervals are equal. |
| 4. | equal path lengths are traversed in equal intervals. |
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