Read the assertion and reason carefully to mark the correct option out of the options given below:
(1) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(2) If both assertion and reason are true but reason is not the correct explanation of the assertion.
(3) If assertion is true but reason is false.
(4) If the assertion and reason both are false.
(5) If assertion is false but reason is true.
Assertion : The average speed of an object may be equal to arithmetic mean of individual speed.
Reason : Average speed is equal to total distance travelled per total time taken.
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
A particle moves along the sides AB, BC, CD of a square of side 25 m with a velocity of 15 ms-1. Its average velocity is
(1) 15 ms-1
(2) 10 ms-1
(3) 7.5 ms-1
(4) 5 ms-1
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)
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)
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
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.
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
A bullet moving with a velocity of 200 cm/s penetrates a wooden block and comes to rest after traversing 4 cm inside it. What velocity is needed for travelling distance of 9 cm in same block?
1. 100 cm/s
2. 136.2 cm/s
3. 300 cm/s
4. 250 cm/s
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 |