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 \(9\) 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
A stone is dropped from a height h. Simultaneously, another stone is thrown up from the ground which reaches a height 4h. The two stones cross each other after time:
1.
2.
3.
4.
Four marbles are dropped from the top of a tower one after the other at a one-second interval. The first one reaches the ground after 4 seconds. When the first one reaches the ground the distances between the first and second, the second and third, and the third and fourth will be, respectively:
1. | 35 m, 25 m, and 15 m | 2. | 30 m, 20 m, and 10 m |
3. | 20 m, 10 m, and 5 m | 4. | 40 m, 30 m, and 20 m |
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.
Two cars are moving in the same direction with the same speed 30 km/hr. They are separated by a distance of 5 km. The speed of a car moving in the opposite direction, if it meets these two cars at an interval of 4 minutes, will be
1. 40 km/hr
2. 45 km/hr
3. 30 km/hr
4. 15 km/hr
Acceleration-time graph of a body is shown.
The corresponding velocity-time graph of the same body is:
1. | 2. | ||
3. | 4. |
Which of the following velocity-time graphs shows a realistic situation for a body in motion?
1. | 2. | ||
3. | 4. |
Which graph represents a uniformly accelerated motion?
1. | 2. | ||
3. | 4. |