R4RIN – MCQs, Mock Tests | IIT JEE IIT JEE Description Of Motion In One Dimension part2

A body is released from the top of a tower of height h metre. It takes T second to reach the ground. Where is the ball at the T / 2 second?

1. at h / 4 metre from the ground
2. at h / 2 metre from the ground
3. at 3h / 4 metre from the ground
4. depends upon the mass and volume of the ball

✅ Correct Answer: 3

A stone falls freely from rest and the total distance covered by it in the last second of its motion equals the distance covered by it in the first three second of its motion. The stone remains in air for

1. 4 s
2. 7 s
3. 7 s
4. 4 s

✅ Correct Answer: 2

A body moving with uniform retardation covers 3 km before its speed is reduced to half its initial value. It comes to rest in another distance of

1. 1 km
2. 2 km
3. 3 km
4. 1/2 km

✅ Correct Answer: 1

stone is dropped from the top of the tower and reaches the ground in 3 s.Then the heigh of the tower is

1. 18.6 m
2. 39.2 m
3. 44.1 m
4. 98 m

✅ Correct Answer: 3

Drops of water fall from the roof of a building 9 m high at regular intervals of time the first drop reaching the ground at the same instant the fourth drop starts its fall. What are the distances of the second and third drops from the roof ?

1. 4 m and 1 m
2. 4 m and 2 m
3. 6 m and 2 m
4. 6 m and 2 m

✅ Correct Answer: 1

A body covers 26 m 28 m 30 m 32 m in 10th s 11th s 12 th s and 13 th s respectively.The body starts

1. from rest and moves with uniform acceleration
2. from rest and moves with uniform velocity
3. with an initial velocity and moves with uniform acceleration
4. with an initial velocity and moves with uniform velocity

✅ Correct Answer: 3

A rifle bullet loses 1 / 20th of its velocity in passing through a plank. The least number of such planks required to just stop the bullet is

1. 5
2. 10
3. 11
4. 20

✅ Correct Answer: 3

A steamer takes 12 days to reach from port A to B. Every day only one steamers sets out from both the ports. How many steamers does each boat meet in the open sea ?

1. 12
2. 13
3. 23
4. 24

✅ Correct Answer: 3

An object fall from rest In the last second of its fall it covers half of the total distance If g = 98 m s-2 then the total height of the fall is

1. 19.6 m
2. 50 m
3. 57 m
4. 78.4 m

✅ Correct Answer: 3

A particle covers 4 m.5 m 6 m and 7 m in 3rd 4th5 th and 6 th second respectively. The particle starts

1. with an initial non-zero velocity and moves with uniform acceleration
2. from rest and moves with uniform velocity
3. with an initial velocity and moves with uniform velocity
4. from rest and moves with uniform acceleration.

✅ Correct Answer: 1

A boy releases a ball from the top of a building It will clear a window 2 m high at a distance 10 m below the top in nearly

1. 1 s
2. 1.3 s
3. 0.6 s
4. 0.13 s

✅ Correct Answer: 4

A drunkard is walking along a straight road He takes 5 steps forward and 3 steps backward followed by 5 steps forwards and 3 steps backward and so on Each step is one metre long and takes one second There is a pit on the road 11 metre away from the starting point The drunkard will fall into the pit after

1. 21 s
2. 29 s
3. 31 s
4. 37 s

✅ Correct Answer: 2

Two bodies begin a free fall from rest the same height 1 second apart How long after the first body begins to fall will the two bodies be 10 apart ?

1. 2 s
2. 3.5 s
3. 0.5 s
4. 1.5 s

✅ Correct Answer: 4

A ball released from a certain height falls 5 m in one second In 4 s it falls through

1. 80 m
2. 40 m
3. 1.25 m
4. 20 m

✅ Correct Answer: 1

A particle starting from rest travels a distance x in first 2 second and a distance y in next 2 second then

1. y =2x
2. y = 3x
3. y = 4x
4. y = x

✅ Correct Answer: 2

A dust packet is dropped from 9th storey of a multi-storeyed building In the first second of its free fall another dust packet is dropped from 7th storey 15m below the 9th storey If both packets reach the ground at same time then height of the building is:

1. 25m
2. 15 m
3. 20 m
4. 16 m

✅ Correct Answer: 3

The distance through which a body falls in the nth second is h The distance through which it falls in the next second is

1. h
2. h + g/2
3. h - g
4. h + g

✅ Correct Answer: 4

A stone is dropped from a certain height which can reach the ground in 5 second If the stone is stopped after 3 second of its fall and then allowed to fall again Then the time taken by the stone to reach the ground for the remaining distance is

1. 4 s
2. 3 s
3. 2 s
4. None of these

✅ Correct Answer: 1

A boy takes 90 second to walk up a stalled escalater However if the escalator is moving and the boy stands on the escalator he is carried up in one minute How much time the boy would take to walk up the moving escalator ?

1. 36 s
2. 40 s
3. 41.25 s
4. 43.75 s

✅ Correct Answer: 1

A body released from a great height falls freely towards the earth Another body is released from the same height exactly one second later The separation between the two bodies two second after the release of the second body is

1. 9.8 m
2. 4.9 m
3. 24.5 m
4. 19.6 m

✅ Correct Answer: 3

A train runs past a telegraph pole in 15 second and through a tunnel 450 metre long in 45 s The length of the train is

1. 225 m
2. 325 m
3. 425 m
4. 450 m

✅ Correct Answer: 1

A ball falls freely from rest The ratio of the distances traveled in first second third and fourth second is

1. 1 : 1 :1 : 2
2. 1 : 1 :1 : 3
3. 1 : 2 :3 : 4
4. 1 : 3 :5 : 7

✅ Correct Answer: 4

Two different masses m and 2m are fallen from height H1 and H2 respectively. First mass takes t second and another takes 2t second then the ratio of H1 and H2 is:

1. 2:01
2. 4:01
3. 0.25:1
4. None of these

✅ Correct Answer: 3

A steam boat goes across a lake and comes back (i) on a quiet day when the water is still and (ii) on a rough day when there is a uniform current so as to help the journey onwards and to impede the journey back . If the speed of the launch on both days was same the time required for complete journey on the rough day as compared to the quiet day will be

1. more
2. less
3. same
4. None of these

✅ Correct Answer: 1

A body of mass 3 kg falls from the multi-storeyed building 100 m high and buries itself 2 m deep in the send. The time of penetration will be

1. 0.09 s
2. 0.9 s
3. 9 s
4. 10 s

✅ Correct Answer: 1

If a -b and c be the distances travelled by the body during xth yth and zth second from start then which of the following relations is true ?

1. a (y - z) + b (z - x) + c (x - y) = 0
2. a (x - y) + b (y - z) + c (z - x) = 0
3. a (z - x) + b (x - y) + c (y - z) = 0
4. ax + by + cz = 0

✅ Correct Answer: 1

If the velocity of a car is increased by 20% then the minimum distance in which it can be stopped increases by

1. 44%
2. 55%
3. 66%
4. 88%

✅ Correct Answer: 1

Two balls A and B are thrown from the top of a water. The ball A is thrown vertically upwards. The ball B is thrown vertically downwards with the same speed. Which of the following is true ?

1. A reaches the ground earlier than B
2. B reaches the ground earlier than A
3. Ball A strikes the ground with higher velocity
4. Both A and B reach the ground at the same time.

✅ Correct Answer: 2

A tiger chases a deer 30 m ahead of it and gains 3 metre in 5 second after the chase began The distance gained by the tiger in 10 second is

1. 6 m
2. 12 m
3. 18 m
4. 20 m

✅ Correct Answer: 2

A body freely falling from rest has a velocity u after it falls through distance h The distance it has to fall down further for its velocity to become double is

1. h
2. 2h
3. 3h
4. 4h

✅ Correct Answer: 3

A particle moving in a straight line with uniform acceleration is observed to be at a distance a from a fixed point initially. It is at distances b c d from the same point after n 2n 3n second. Then (d - a) =

1. (c - b)
2. 2(c - b)
3. 3(c - b)
4. 4(c - b)

✅ Correct Answer: 3