NEET Physics Motion in a Straight Line MCQs Set A

a)

b)

c)

d)

Answer:

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:  x < 0, v < 0, a > 0

Question:

a)

b) The displacement in time T must always take nonnegative values

c) The acceleration is always a non-negative number

d) The motion has no turning points

Answer: 

Question:

a)

b)

c)

d)

Answer:

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: 8 m

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: 2gH = nu² (n – 2)

Question:  A body starts from rest at time t = 0, the acceleration time graph is shown in the figure. The maximum velocity attained by the body will be

a) 55 m/s 

b) 650 m/s

c) 550 m/s

d) 110 m/s

Answer: 55 m/s

Question:  A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = bx^–2n where b and n are constants and x is the position of the particle. The acceleration of the particle as d function of x,

a)

b)

c)

d)

Answer:

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: Assertion is correct, reason is incorrect

Question:  Two stones are thrown up simultaneously from the edge of a cliff 240 m high with initial speed of 10 m/s and 40 m/s respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first?  (Assume stones do not rebound after hitting the ground and neglect air resistance, take g = 10 m/ s²) (The figures are schematic and not drawn to scale)

a)

b)

c)

d)

Answer:

Question:    A body is thrown vertically upwards from A, the top of the tower, reaches the ground in time t₁. If it is thrown vertically downwards from A with the same speed, it reaches the ground in time t₂. If it is allowed to fall freely from A, then the time it takes to reach the ground is given by

a)

b)

c)

d)

Answer:

Question:  If the velocity of a particle is v = At + Bt², where A and B are constants, then the distance travelled by it between 1s and 2s is :

a)

b)

c)

d)

Answer:

Question:  Two bodies begin a free fall from the same height at a time interval of N s. If vertical separation between the two bodies is 1 after n second from the start of the first body, then n is equal to

a)

b)

c)

d)

Answer:

Question:  Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t₁. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t . The time taken by her to walk up on the moving escalator will be:

a)

b)

c)

d)

Answer:

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: 5 s

Question:   A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time?

a)

b)

c)

d)

Answer:

Question:

a) 1 m/s, 3 m/s

b) 1 m/s, 3.5 m/s

c) 2 m/s, 4 m/s

d) 1.5 m/s, 3 m/s

Answer: 1 m/s, 3 m/s

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:  12 ms^–2

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: 3.75 m

Question:   All the graphs below are intended to represent the samemotion. One of them does it incorrectly. Pick it up.

a)

b)

c)

d)

Answer:

Question:   A boy running on a horizontal road at 8 km/h finds the rain falling vertically. He increases his speed to 12 km/h and finds that the drops makes 30° with the vertical. The speed of rain with respect to the road is

a)

b)

c)

d)

Answer:

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: 15, 20, 15

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:  8g

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:   Which graph corresponds to an object moving with a constant negative acceleration and a positive velocity ?

a)

b)

c)

d)

Answer:

Question:  A particle starts sliding down a frictionless inclined plane. If S_n is the distance travelled by it from time t = n – 1 sec to t = n sec, the ratio S_n/S_n+1 is

a)

b)

c)

d)

Answer:

Question:

a) 22 m/s

b) 33 m/s

c) 44 m/s

d) 11 m/s

Answer:  22 m/s

Question:

a)

b)  None of these

c)

d)

Answer:

Question:

a) 0 m

b) 4 m

c) None of these

d) 6 m

Answer: 0 m

Question:  The distance travelled by a body moving along a line in time t is proportional to t³. The acceleration-time (a, t) graph for the motion of the body will be

a)

b)

c)

d) None of these

Answer:

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: 490 m/s²

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:  50 km

Question:

a) b, 2 c

b) 2 c, – 4 d

c) – b, 2 c

d) b, – 4 d

Answer: b, 2 c

Question:

a) go on increasing with time

b) go on decreasing with time

c)

d)

Answer:  go on increasing with time

Question:   A point moves with uniform acceleration and V₁, V₂, V₃ denote the average velocities in three successive intervals of time t₁, t₂, t₃. Which of the following relations is correct?

a)

b)

c)

d) None of these

Answer:

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: 15 m

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: 4

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: parabola

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:  None of these