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 |
Two particles \(A\) and \(B\) are moving in a uniform circular motion in concentric circles of radii \(r_A\) and \(r_B\) with speeds \(v_A\) and \(v_B\) respectively. Their time periods of rotation are the same. The ratio of the angular speed of \(A\) to that of \(B\) will be:
1. | \( 1: 1 \) | 2. | \(r_A: r_B \) |
3. | \(v_A: v_B \) | 4. | \(r_B: r_A\) |
The speed of a swimmer in still water is \(20~\text{m/s}.\) The speed of river water is \(10~\text{m/s}\) and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path, the angle at which he should make his strokes with respect to the north is given by:
1. | \(45^{\circ}\) west of north | 2. | \(30^{\circ}\) west of north |
3. | \(0^{\circ}\) west of north | 4. | \(60^{\circ}\) west of north |
Two bullets are fired horizontally and simultaneously towards each other from the rooftops of two buildings (building being \(100~\text{m}\) apart and being of the same height of \(200~\text{m}\)) with the same velocity of \(25~\text{m/s}.\) When and where will the two bullets collide?
\((g = 10~\text{m/s}^2)\)
1. | After \(2~\text{s}\) at a height of \(180~\text{m}\) |
2. | After \(2~\text{s}\) at a height of \(20~\text{m}\) |
3. | After \(4~\text{s}\) at a height of \(120~\text{m}\) |
4. | They will not collide. |
The velocity of a projectile at the initial point \(A\) is \(2\hat i+3\hat j~\text{m/s}.\) Its velocity (in m/s) at the point \(B\) is:
1. | \(-2\hat i+3\hat j~\) | 2. | \(2\hat i-3\hat j~\) |
3. | \(2\hat i+3\hat j~\) | 4. | \(-2\hat i-3\hat j~\) |
A projectile is fired from the surface of the earth with a velocity of \(5~\text{m/s}\) and at an angle \(\theta\) with the horizontal. Another projectile fired from another planet with a velocity of \(3~\text{m/s}\) at the same angle follows a trajectory that is identical to the trajectory of the projectile fired from the Earth. The value of the acceleration due to gravity on the other planet is: (given \(g=9.8~\text{m/s}^2\) )
1. \(3.5~\text{m/s}^2\)
2. \(5.9~\text{m/s}^2\)
3. \(16.3~\text{m/s}^2\)
4. \(110.8~\text{m/s}^2\)
1. | Acceleration is along \((\text{-}\vec R )\). |
2. | Magnitude of the acceleration vector is \(\frac{v^2}{R}\), where \(v\) is the velocity of the particle. |
3. | Magnitude of the velocity of the particle is \(8\) m/s. |
4. | Path of the particle is a circle of radius \(4\) m. |
Two particles \({A}\) and \({B}\), move with constant velocities \(\vec{v}_1\) and \(\vec{v}_2\) respectively. At the initial moment, their position vectors are \(\vec{r}_1\) and \(\vec r_2\) respectively. The conditions for particles \({A}\) and \({B}\) for their collision will be:
1. | \(\dfrac{\vec{r}_1-\vec{r}_2}{\left|\vec{r}_1-\vec{r}_2\right|}=\dfrac{\vec{v}_2-\vec{v}_1}{\left|\vec{v}_2-\vec{v}_1\right|}\) |
2. | \(\vec{r}_1 \cdot \vec{v}_1=\vec{r}_2 \cdot \vec{v}_2\) |
3. | \(\vec{r}_1 \times \vec{v}_1=\vec{r}_2 \times \vec{v}_2\) |
4. | \(\vec{r}_1-\vec{r}_2=\vec{v}_1-\vec{v}_2\) |
A ship \(A\) is moving westward with a speed of \(10~\text{kmph}\) and a ship \(B,\) \(100 ~\text{km}\) south of \(A,\) is moving northward with a speed of \(10~\text{kmph}.\) The time after which the distance between them becomes the shortest is:
1. \(0~\text{h}\)
2. \(5~\text{h}\)
3. \(5\sqrt{2}~\text{h}\)
4. \(10\sqrt{2}~\text{h}\)
1. | \(0.15\) m/s2 | 2. | \(0.18\) m/s2 |
3. | \(0.2\) m/s2 | 4. | \(0.1\) m/s2 |