A particle is moving along a circle of radius \(R \) with constant speed \(v_0\). What is the magnitude of change in velocity when the particle goes from point \(A\) to \(B \) as shown?
1. | \( 2{v}_0 \sin \frac{\theta}{2} \) | 2. | \(v_0 \sin \frac{\theta}{2} \) |
3. | \( 2 v_0 \cos \frac{\theta}{2} \) | 4. | \(v_0 \cos \frac{\theta}{2}\) |
Which of the following statements is incorrect?
1. | The average speed of a particle in a given time interval cannot be less than the magnitude of the average velocity. |
2. | It is possible to have a situation \(\left|\frac{d\overrightarrow {v}}{dt}\right|\neq0\) but \(\frac{d\left|\overrightarrow{v}\right|}{dt}=0\) |
3. | The average velocity of a particle is zero in a time interval. It is possible that instantaneous velocity is never zero in that interval. |
4. | It is possible to have a situation in which \(\left|\frac{d\overrightarrow{v}}{dt}\right|=0\) but \(\frac{d\left|\overrightarrow{v}\right|}{dt}\neq0\) |
A man is walking on a horizontal road at a speed of \(4~\text{km/hr}.\) Suddenly, the rain starts vertically downwards with a speed of \(7~\text{km/hr}.\) The magnitude of the relative velocity of the rain with respect to the man is:
1. \(\sqrt{33}~\text{km/hr}\)
2. \(\sqrt{65}~\text{km/hr}\)
3. \(8~\text{km/hr}\)
4. \(4~\text{km/hr}\)
If a body is accelerating, then:
1. | it must speed up. |
2. | it may move at the same speed. |
3. | it may move with the same velocity. |
4. | it must slow down. |
A shell is fired vertically upward with a velocity of \(20\) m/s from a trolley moving horizontally with a velocity of \(10\) m/s. A person on the ground observes the motion of the shell-like a parabola whose horizontal range is: (\(g= 10~\text{m/s}^2\))
1. | \(20\) m | 2. | \(10\) m |
3. | \(40\) m | 4. | \(400\) m |
An object of mass m is projected from the ground with a momentum \(p\) at such an angle that its maximum height is \(\frac{1}{4}\)th of its horizontal range. Its minimum kinetic energy in its path will be:
1. | \(\frac{p^2}{8 m} \) | 2. | \(\frac{p^2}{4 m} \) |
3. | \(\frac{3 p^2}{4 m} \) | 4. | \(\frac{p^2}{m}\) |
A particle moving on a curved path possesses a velocity of \(3\) m/s towards the north at an instant. After \(10\) s, it is moving with speed \(4\) m/s towards the west. The average acceleration of the particle is:
1. | \(0.25~\text{m/s}^2,\) \(37^{\circ}\) south to east. |
2. | \(0.25~\text{m/s}^2,\) \(37^{\circ}\) west to north. |
3. | \(0.5~\text{m/s}^2,\) \(37^{\circ}\) east to north. |
4. | \(0.5~\text{m/s}^2,\) \(37^{\circ}\) south to west. |
A man can row a boat with a speed of \(10~\text{kmph}\) in still water. The river flows at \(6~\text{kmph}.\) If he crosses the river from one bank to the other along the shortest possible path, the time taken to cross the river of width \(1~\text{km}\) is:
1. \(\frac{1}{8}~\text{hr}\)
2. \(\frac{1}{4}~\text{hr}\)
3. \(\frac{1}{2}~\text{hr}\)
4. \(1~\text{hr}\)
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 \(\mathrm{N\text-W}\) |
Two bullets are fired simultaneously horizontally and at different speeds from the same place. Which bullet will hit the ground first? (Air resistance is neglected)
1. | The faster one |
2. | The slower one |
3. | Depends on masses |
4. | Both will reach simultaneously |