A thief is running away on a straight road in a jeep moving with a speed of \(9\) m/s. A policeman chases him on a motorcycle moving at a speed of \(10\) m/s. If the instantaneous separation of the jeep from the motorcycle is \(100\) m, how long will it take for the policeman to catch the thief?
1. \(1\) s
2. \(19\) s
3. \(90\) s
4. \(100\) s
If the body covers one-third distance at speed v1, next one third at speed v2 and last one third at speed v3, then average speed will be
1.
2.
3.
4.
A body has speed V, 2V and 3V in first 1/3 of distance S, second 1/3 of S and third 1/3 of S respectively. Its average speed will be
1. V
2. 2V
3.
4.
A car A is travelling on a straight level road with a uniform speed of 60 km/h. It is followed by another car B which is moving with a speed of 70 km/h. When the distance between them is 2.5 km, the car B is given a deceleration of 20 km/h2. After how much time will B catch up with A
1. 1 hr
2. 1/2 hr
3. 1/4 hr
4. 1/8 hr
A car travels a distance S on a straight road in two hours and then returns to the starting point in the next three hours. Its average velocity is
1. S/5
2. 2S/5
3. S/2 + S/3
4. None of the above
1. | \(-\frac{1}{2}\left(a\omega^2\sin\omega t\right)t^2\) | 2. | \(a\omega \sin \omega t\) |
3. | \(a\omega \cos \omega t\) | 4. | \(a\sin \omega t\) |
The displacement of the particle varies with time according to the relation . Then the velocity of the particle is
1.
2.
3.
4. None of these
A particle moves along the sides \(AB,BC,CD\) of a square of side \(25~\text{m}\) with a speed of \(15~\text{ms}^{-1}\). Its average velocity is:
1. \(15~\text{ms}^{-1}\)
2. \(10~\text{ms}^{-1}\)
3. \(7.5~\text{ms}^{-1}\)
4. \(5~\text{ms}^{-1}\)
If the velocity of a particle is (10 + 2t2) m/s, then the average acceleration of the particle between 2 sec and 5 sec is:
1. 2 m/s2
2. 4 m/s2
3. 12 m/s2
4. 14 m/s2
Read the assertion and reason carefully to mark the correct option out of the options given below:
Assertion (A): | The average and instantaneous velocities have the same value in a uniform motion. |
Reason (R): | In uniform motion, the velocity of an object increases uniformly. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |