Given below are two statements:
Assertion (A): | Position-time graph of a stationary object is a straight line parallel to the time axis. |
Reason (R): | For a stationary object, the position does not change with time. |
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. | Both (A) and (R) are false. |
The acceleration of a particle starting from rest varies with time according to the relation A = – aω2sinωt. The displacement of this particle at a time t will be:
1.
2.
3.
4.
A thief is running away on a straight road in a jeep moving with a speed of 9 ms–1. A policeman chases him on a motor cycle moving at a speed of 10 ms–1. 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 |
A particle is projected upwards. The times corresponding to height h while ascending and while descending are t1 and t2 respectively. The velocity of projection will be:
1. gt1
2. gt2
3.
4.
In the following graph, the distance travelled by the body in metres is:
1. | \(200\) | 2. | \(250\) |
3. | \(300\) | 4. | \(400\) |
The velocity-time graph of a body moving in a straight line is shown in the figure. The displacement and distance travelled by the body in 6 seconds are, respectively, :
1. 8 m, 16 m
2. 16 m, 8 m
3. 16 m, 16 m
4. 8 m, 8 m
A stone dropped from a building of height h and reaches the earth after t seconds. From the same building, if two stones are thrown (one upwards and other downwards) with the same velocity u and they reach the earth surface after t1 and t2 seconds respectively, then:
1.
2.
3.
4.
A particle moving in a straight line covers half the distance with a speed of \(3~\text{m/s}\). The other half of the distance is covered in two equal time intervals with speeds of \(4.5~\text{m/s}\) and \(7.5~\text{m/s}\) respectively. The average speed of the particle during this motion is:
1. \(4.0~\text{m/s}\)
2. \(5.0~\text{m/s}\)
3. \(5.5~\text{m/s}\)
4. \(4.8~\text{m/s}\)
A body starts to fall freely under gravity. The distances covered by it in first, second and third second will be in the ratio:
1. 1 : 3 : 5
2. 1 : 2 : 3
3. 1 : 4 : 9
4. 1 : 5 : 6
A student is standing at a distance of 50 metres from the bus. As soon as the bus begins its motion with an acceleration of 1 ms–2, the student starts running towards the bus with a uniform velocity u. Assuming the motion to be along a straight road, the minimum value of u, so that the student is able to catch the bus is:
1. 5 ms–1
2. 8 ms–1
3. 10 ms–1
4. 12 ms–1