NEET Physics Motion in a Straight Line MCQs Set A

Question.  A lift is coming from 8th floor and is just about to reach 4th floor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct?
(a) x < 0, v < 0, a > 0
(b) x > 0, v < 0, a > 0
(c) x > 0, v < 0, a < 0
(d) x > 0, v > 0, a < 0

Answer: A

Question.  The displacement of a particle is given by x = (t – 2)² where x is in metre and t in second. The distance covered by the particle in first 4 seconds is
(a) 8 m
(b) 12 m
(c) 16 m
(d) 4 m

Answer: A

Question.  From a tower of height H, a particle is thrown vertically upwards with a speed u. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is
(a) 2gH = nu² (n – 2)
(b) 2gH = n²u²
(c) gH = (n – 2)²u²d
(d) gH = (n – 2)u²

Answer: A

Question.
Assertion : Velocity-time graph for an object in uniform motion along a straight path is a straight line parallel to the time axis.
Reason : In uniform motion of an object velocity increases as the square of time elapsed.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct.
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer: A

Question.  From a balloon moving upwards with a velocity of 12 ms^–1, a packet is released when it is at a height of 65 m from the ground. The time taken by it to reach the ground is (g = 10 ms^–2)
(a) 5 s
(b) 8 s
(c) 4 s
(d) 7 s

Answer: A

Question.  The motion of a particle along a straight line is described by equation :
x = 8 + 12t – t³
where x is in metre and t in second. The retardation of the particle when its velocity becomes zero, is
(a) 12 ms^–2
(b) 6 ms^–2
(c) zero
(d) 24 ms^–2

Answer: A

Question.  The water drops fall at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at an instant when the first drop touches the ground. How far above the ground is the second drop at that instant ? (Take g = 10 m/s²)
(a) 3.75 m
(b) 5.00 m
(c) 2.50 m
(d) 1.25 m

Answer: A

Question.  A juggler keeps on moving four balls in the air throwing the balls after intervals. When one ball leaves his hand (speed = 20 ms–1) the position of other balls (height in m) will be (Take g = 10 ms^–2)
(a) 15, 20, 15
(b) 5, 15, 20
(c) 5, 10, 20
(d) 10, 20, 10

Answer: A

Question. A particle when thrown, moves such that it passes from same height at 2 and 10 seconds, then this height h is
(a) 8g
(b) 10g
(c) g
(d) 5g

Answer: A

Question. A ball is dropped from a height of 5 m onto a sandy floor and penetrates the sand upto 10 cm before coming to rest. Find the retardation of the ball in sand assuming it to be uniform.
(a) 490 m/s²
(b) 610 m/s²
(c) 720 m/s²
(d) 810 m/s²

Answer: A

Question.  A bird flies with a speed of 10 km/h and a car moves with uniform speed of 8 km/h. Both start from B towards A (BA = 40km) at the same instant. The bird having reached A, flies back immediately to meet the approaching car. As soon as it reaches the car, it flies back to A. The bird repeats this till both the car and the bird reach A simultaneously. The total distance flown by the bird is
(a) 50 km
(b) 30 k m
(c) 40 km
(d) 80 km

Answer: A

Question.   Two fixed points A and B are 20 metres apart. At time t = 0, the distance between a third point C and A is 20 meters and the distance between C and B is 10 metres. The component of velocity of point C along both CA and CB at any instant is 5m/s. Then the distance between A and C at the instant all the three points are collinear will be
(a) 15 m
(b) 10 m
(c) 25 m
(d) 5 m

Answer: A

Question.  From a pole of height 10 m, a stone is thrown vertically upwards with a speed 5 m/s. The time taken by the stone, to hit the ground, is n times that taken by it to reach the highest point of its path. The value of n is  [take g = 10 m/s²]
(a) 4
(b) 5
(c) 3
(d) 2

Answer: A

Question. The graph between displacement and time for a particle moving with uniform acceleration is a/an
(a) parabola
(b) ellipse
(c) Both
(d) None of these

Answer: A

Question. The acceleration of a moving body can be found from
(a) None of these
(b) slope of distance-time graph
(c) area under distance -time graph
(d) area under velocity - time graph

Answer: A