Motion in a Straight Line- 2 Practice Questions - DPP for NEET

 Page 1


DIRECTIONS (Q.1-Q.19) : There are 19 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A stone is dropped from a minar of height h and it reaches
after t seconds on earth. From the same minar if two stones
are thrown (one upwards and other downwards) with the same
velocity u and they reach the earth surface after t
1
 and t
2
seconds respectively, then
(a)
12
t tt =- (b)
12
2
tt
t
+
=
(c)
12
t tt = (d)
22
12
= t tt
Q.2 A ball is projected upwards from a height h above the surface
of the earth with velocity v . The time at which the ball strikes
the ground is
(a)
2
v hg
g
2
+ (b)
11
vh
gg
éù
2
-+
êú
ëû
(c)
2
11
éù
2
++
êú
ëû
v gh
g
v
(d)
2
1
vg
v
gh
éù
2
++
êú
ëû
Q.3 A man throws balls with the same speed vertically upwards,
one after the other at an interval of 2 seconds. What should
be the speed of the throw so that more than two balls are in
the sky at any time? (Given g = 9.8 m/s
2
)
(a) At least 0.8 m/s
(b) Any speed less than 19.6 m/s
(c) Only with speed 19.6 m/s
(d) More than 19.6 m/s
Page 2


DIRECTIONS (Q.1-Q.19) : There are 19 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A stone is dropped from a minar of height h and it reaches
after t seconds on earth. From the same minar if two stones
are thrown (one upwards and other downwards) with the same
velocity u and they reach the earth surface after t
1
 and t
2
seconds respectively, then
(a)
12
t tt =- (b)
12
2
tt
t
+
=
(c)
12
t tt = (d)
22
12
= t tt
Q.2 A ball is projected upwards from a height h above the surface
of the earth with velocity v . The time at which the ball strikes
the ground is
(a)
2
v hg
g
2
+ (b)
11
vh
gg
éù
2
-+
êú
ëû
(c)
2
11
éù
2
++
êú
ëû
v gh
g
v
(d)
2
1
vg
v
gh
éù
2
++
êú
ëû
Q.3 A man throws balls with the same speed vertically upwards,
one after the other at an interval of 2 seconds. What should
be the speed of the throw so that more than two balls are in
the sky at any time? (Given g = 9.8 m/s
2
)
(a) At least 0.8 m/s
(b) Any speed less than 19.6 m/s
(c) Only with speed 19.6 m/s
(d) More than 19.6 m/s
2
DPP/ P 04
Q.4 If a ball is thrown vertically upwards with speed u, the
distance covered during the last t second of its ascent is
(a)
2
1
2
gt (b)
2
1
2
ut gt - (c) (u – gt)t (d) ut d
Q.5 A ball is thrown vertically upwards. Which of the following
graphs represent velocity-time graph of the ball during its
flight? (air resistance is neglected)
(a)
t
v
(b)
t
v
(c)
t
v
1
(d)
t
v
Q.6 A ball is dropped vertically from a height d above the
ground. It hits the ground and bounces up vertically to a
height d/2. Neglecting subsequent motion and air
resistance, its velocity v varies with the height h above the
ground is
(a) 
h
d
v
(b) 
h
d
v
(c)
h
d
v
(d)
h
d
v
Q.7 P , Q and R are three balloons ascending with velocities U,
4U and 8U respectively. If stones of the same mass be
dropped from each, when they are at the same height, then
(a) They reach the ground at the same time
(b) Stone from P reaches the ground first
(c) Stone from R reaches the ground first
(d) Stone from Q reaches the ground first
Q.8 A body is projected up with a speed 'u' and the time taken
by it is T to reach the maximum height H. Pick out the
correct statement
(a) It reaches H/2 in T/2 sec
(b) It acquires velocity u/2 in T/2 sec
(c) Its velocity is u/2 at H/2
(d) Same velocity at 2T
Q.9 Time taken by an object falling from rest to cover the height
of h
1
 and h
2
 is respectively t
1
 and t
2
 then the ratio of t
1
 to t
2
is
(a) h
1
 : h
2
(b) 
12
: hh (c)  h
1
 : 2h
2
(d)2h
1
 : h
2
Q.10 Three different objects of masses m
1
, m
2
 and m
3
 are allowed
to fall from rest and from the same point 'O' along three
different frictionless paths. The speeds of the three objects,
on reaching the ground, will be in the ratio of
(a) m
1
 : m
2
 : m
3
 (b) m
1
 : 2m
2
 : 3m
3
 (c) 1 : 1 : 1 (d)
1 23
1 11
::
m mm
Q.11 From the top of a tower, a particle is thrown vertically
downwards with a velocity of 10 m/s. The ratio of the
distances, covered by it in the 3
rd
 and 2
nd
 seconds of the
motion is (Take g = 10m/s
2
)
(a) 5 : 7 (b) 7 : 5 (c) 3 : 6 (d) 6 : 3
Q.12 A body falls from a height h = 200 m. The ratio of distance
travelled in each 2 second during t = 0 to t = 6 second of
the journey is
(a) 1 : 4 : 9 (b) 1 : 2 : 4
(c) 1 : 3 : 5 (d) 1 : 2 : 3
Q.13 The effective acceleration of a body , when thrown upwards
with acceleration a will be :
(a)
2
ag -
(b)
22
ag +
(c)(a – g) (d)(a + g)
Q.14 An aeroplane is moving with a velocity u. It drops a packet
from a height h. The time t taken by the packet in reaching
the ground will be
(a)  
2g
h
æö
ç÷
èø
(b)
2u
g
æö
ç÷
èø
(c)
2
h
g
æö
ç÷
èø
(d)
2h
g
æö
ç÷
èø
Page 3


DIRECTIONS (Q.1-Q.19) : There are 19 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A stone is dropped from a minar of height h and it reaches
after t seconds on earth. From the same minar if two stones
are thrown (one upwards and other downwards) with the same
velocity u and they reach the earth surface after t
1
 and t
2
seconds respectively, then
(a)
12
t tt =- (b)
12
2
tt
t
+
=
(c)
12
t tt = (d)
22
12
= t tt
Q.2 A ball is projected upwards from a height h above the surface
of the earth with velocity v . The time at which the ball strikes
the ground is
(a)
2
v hg
g
2
+ (b)
11
vh
gg
éù
2
-+
êú
ëû
(c)
2
11
éù
2
++
êú
ëû
v gh
g
v
(d)
2
1
vg
v
gh
éù
2
++
êú
ëû
Q.3 A man throws balls with the same speed vertically upwards,
one after the other at an interval of 2 seconds. What should
be the speed of the throw so that more than two balls are in
the sky at any time? (Given g = 9.8 m/s
2
)
(a) At least 0.8 m/s
(b) Any speed less than 19.6 m/s
(c) Only with speed 19.6 m/s
(d) More than 19.6 m/s
2
DPP/ P 04
Q.4 If a ball is thrown vertically upwards with speed u, the
distance covered during the last t second of its ascent is
(a)
2
1
2
gt (b)
2
1
2
ut gt - (c) (u – gt)t (d) ut d
Q.5 A ball is thrown vertically upwards. Which of the following
graphs represent velocity-time graph of the ball during its
flight? (air resistance is neglected)
(a)
t
v
(b)
t
v
(c)
t
v
1
(d)
t
v
Q.6 A ball is dropped vertically from a height d above the
ground. It hits the ground and bounces up vertically to a
height d/2. Neglecting subsequent motion and air
resistance, its velocity v varies with the height h above the
ground is
(a) 
h
d
v
(b) 
h
d
v
(c)
h
d
v
(d)
h
d
v
Q.7 P , Q and R are three balloons ascending with velocities U,
4U and 8U respectively. If stones of the same mass be
dropped from each, when they are at the same height, then
(a) They reach the ground at the same time
(b) Stone from P reaches the ground first
(c) Stone from R reaches the ground first
(d) Stone from Q reaches the ground first
Q.8 A body is projected up with a speed 'u' and the time taken
by it is T to reach the maximum height H. Pick out the
correct statement
(a) It reaches H/2 in T/2 sec
(b) It acquires velocity u/2 in T/2 sec
(c) Its velocity is u/2 at H/2
(d) Same velocity at 2T
Q.9 Time taken by an object falling from rest to cover the height
of h
1
 and h
2
 is respectively t
1
 and t
2
 then the ratio of t
1
 to t
2
is
(a) h
1
 : h
2
(b) 
12
: hh (c)  h
1
 : 2h
2
(d)2h
1
 : h
2
Q.10 Three different objects of masses m
1
, m
2
 and m
3
 are allowed
to fall from rest and from the same point 'O' along three
different frictionless paths. The speeds of the three objects,
on reaching the ground, will be in the ratio of
(a) m
1
 : m
2
 : m
3
 (b) m
1
 : 2m
2
 : 3m
3
 (c) 1 : 1 : 1 (d)
1 23
1 11
::
m mm
Q.11 From the top of a tower, a particle is thrown vertically
downwards with a velocity of 10 m/s. The ratio of the
distances, covered by it in the 3
rd
 and 2
nd
 seconds of the
motion is (Take g = 10m/s
2
)
(a) 5 : 7 (b) 7 : 5 (c) 3 : 6 (d) 6 : 3
Q.12 A body falls from a height h = 200 m. The ratio of distance
travelled in each 2 second during t = 0 to t = 6 second of
the journey is
(a) 1 : 4 : 9 (b) 1 : 2 : 4
(c) 1 : 3 : 5 (d) 1 : 2 : 3
Q.13 The effective acceleration of a body , when thrown upwards
with acceleration a will be :
(a)
2
ag -
(b)
22
ag +
(c)(a – g) (d)(a + g)
Q.14 An aeroplane is moving with a velocity u. It drops a packet
from a height h. The time t taken by the packet in reaching
the ground will be
(a)  
2g
h
æö
ç÷
èø
(b)
2u
g
æö
ç÷
èø
(c)
2
h
g
æö
ç÷
èø
(d)
2h
g
æö
ç÷
èø
DPP/ P 04
3
Q.15 T wo trains, each 50 m long are travelling in opposite direction
with velocity 10 m/s and 15 m/s. The time of crossing is
(a) 2s (b) 4s
(c)
23s
(d) 43s
Q.16 A train of 150 metre length is going towards north direction
at a speed of 10 m/s. A parrot flies at the speed of 5 m/s
towards south direction parallel to the railway track. The
time taken by the parrot to cross the train is
(a) 12 sec (b) 8 sec
(c) 15 sec (d) 10 sec
Q.17 The distance between two particles is decreasing at the rate
of 6 m/sec. If these particles travel with same speeds and in
the same direction, then the separation increase at the rate
of 4 m/s. The particles have speeds as
(a) 5 m/sec; 1 m/sec (b) 4 m/sec; 1 m/sec
(c) 4 m/sec; 2 m/sec (d) 5 m/sec; 2 m/sec
Q.18 A train is moving towards east and a car is along north, both
with same speed. The observed direction of car to the
passenger in the train is
(a) East-north direction (b) West-north direction
(c) South-east direction (d) None of these
Q.19 An express train is moving with a velocity v
1
. Its driver
finds another train is moving on the same track in the same
direction with velocity v
2
. To escape collision, driver applies
a retardation a on the train, the minimum time of escaping
collision will be
(a)
12
-
=
vv
t
a
(b)
22
12
1
2
-
=
vv
t
(c) Both (a) and (b) (d) None of these
DIRECTIONS (Q.20-Q.22) : In the following questions, more
than one of the answers  given are correct. Select the correct
answers and mark it according to the following codes:
Codes :
(a) 1, 2 and 3 are correct ( b) 1 and 2 are correct
(c) 2 and 4 are correct ( d) 1 and 3 are correct
Q.20 Two particles move simultaneously from two points A and B,
300m apart. The particle at A, starts towards B with a velocity
of 25 m/s and that at B, moves normal to the former with a
velocity of 20 m/s.
(1) The relative velocity of the particle at A, w .r.t. that at B is
32.02 m/s
(2) The relative velocity of the particle at A, w .r.t. that at B is
12.04 m/s
(3) They are closest to each other after 7.32 sec.
(4) They are closest to each other after 4.25 sec.
Q.21 A plane is to fly due north. The speed of the plane relative
to the air is 200 km/h, and the wind is blowing from west
to east at 90 km/h.
(1) The plane should head in a direction of sin
–1
 (0.45)
(2) The plane should head in a direction of sin
–1
 (0.60)
(3) The relative velocity of plane w .r.t. ground is 179 km/h
(4) The relative velocity of plane w .r.t. ground is 149 km/h
Q.22 From the top of a multi-storeyed building 40m tall, a boy
projects a stone vertically upwards with an initial velocity
of 10 ms
–1
 such that it eventually falls to the ground.
(1) After 4 s the stone will strike the ground
(2) After 2 s the stone will pass through the point from
where it was projected
(3) Its velocity when it strikes the ground is 30 m/s
(4) Its velocity when it strikes the ground is 40 m/s
DIRECTIONS (Q.23-Q.25) : Read the passage given below
and answer the questions that follows :
When an airplane flies, its total velocity with respect to the
ground is v
total
 = v
plane
 + v
wind
,
where v
plane
 denotes the plane’s velocity through motionless air,
and v
wind
 denotes the wind’s velocity .  Crucially , all the quantities
in this equation are vectors.  The magnitude of a velocity vector
is often called the “speed.”
Consider an airplane whose speed through motionless air is 100
meters per second (m/s).  To reach its destination, the plane must
fly east.
The “heading” of a plane is in the direction in which the nose of
the plane points. So, it is the direction in which the engines propel
the plane.
Page 4


DIRECTIONS (Q.1-Q.19) : There are 19 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A stone is dropped from a minar of height h and it reaches
after t seconds on earth. From the same minar if two stones
are thrown (one upwards and other downwards) with the same
velocity u and they reach the earth surface after t
1
 and t
2
seconds respectively, then
(a)
12
t tt =- (b)
12
2
tt
t
+
=
(c)
12
t tt = (d)
22
12
= t tt
Q.2 A ball is projected upwards from a height h above the surface
of the earth with velocity v . The time at which the ball strikes
the ground is
(a)
2
v hg
g
2
+ (b)
11
vh
gg
éù
2
-+
êú
ëû
(c)
2
11
éù
2
++
êú
ëû
v gh
g
v
(d)
2
1
vg
v
gh
éù
2
++
êú
ëû
Q.3 A man throws balls with the same speed vertically upwards,
one after the other at an interval of 2 seconds. What should
be the speed of the throw so that more than two balls are in
the sky at any time? (Given g = 9.8 m/s
2
)
(a) At least 0.8 m/s
(b) Any speed less than 19.6 m/s
(c) Only with speed 19.6 m/s
(d) More than 19.6 m/s
2
DPP/ P 04
Q.4 If a ball is thrown vertically upwards with speed u, the
distance covered during the last t second of its ascent is
(a)
2
1
2
gt (b)
2
1
2
ut gt - (c) (u – gt)t (d) ut d
Q.5 A ball is thrown vertically upwards. Which of the following
graphs represent velocity-time graph of the ball during its
flight? (air resistance is neglected)
(a)
t
v
(b)
t
v
(c)
t
v
1
(d)
t
v
Q.6 A ball is dropped vertically from a height d above the
ground. It hits the ground and bounces up vertically to a
height d/2. Neglecting subsequent motion and air
resistance, its velocity v varies with the height h above the
ground is
(a) 
h
d
v
(b) 
h
d
v
(c)
h
d
v
(d)
h
d
v
Q.7 P , Q and R are three balloons ascending with velocities U,
4U and 8U respectively. If stones of the same mass be
dropped from each, when they are at the same height, then
(a) They reach the ground at the same time
(b) Stone from P reaches the ground first
(c) Stone from R reaches the ground first
(d) Stone from Q reaches the ground first
Q.8 A body is projected up with a speed 'u' and the time taken
by it is T to reach the maximum height H. Pick out the
correct statement
(a) It reaches H/2 in T/2 sec
(b) It acquires velocity u/2 in T/2 sec
(c) Its velocity is u/2 at H/2
(d) Same velocity at 2T
Q.9 Time taken by an object falling from rest to cover the height
of h
1
 and h
2
 is respectively t
1
 and t
2
 then the ratio of t
1
 to t
2
is
(a) h
1
 : h
2
(b) 
12
: hh (c)  h
1
 : 2h
2
(d)2h
1
 : h
2
Q.10 Three different objects of masses m
1
, m
2
 and m
3
 are allowed
to fall from rest and from the same point 'O' along three
different frictionless paths. The speeds of the three objects,
on reaching the ground, will be in the ratio of
(a) m
1
 : m
2
 : m
3
 (b) m
1
 : 2m
2
 : 3m
3
 (c) 1 : 1 : 1 (d)
1 23
1 11
::
m mm
Q.11 From the top of a tower, a particle is thrown vertically
downwards with a velocity of 10 m/s. The ratio of the
distances, covered by it in the 3
rd
 and 2
nd
 seconds of the
motion is (Take g = 10m/s
2
)
(a) 5 : 7 (b) 7 : 5 (c) 3 : 6 (d) 6 : 3
Q.12 A body falls from a height h = 200 m. The ratio of distance
travelled in each 2 second during t = 0 to t = 6 second of
the journey is
(a) 1 : 4 : 9 (b) 1 : 2 : 4
(c) 1 : 3 : 5 (d) 1 : 2 : 3
Q.13 The effective acceleration of a body , when thrown upwards
with acceleration a will be :
(a)
2
ag -
(b)
22
ag +
(c)(a – g) (d)(a + g)
Q.14 An aeroplane is moving with a velocity u. It drops a packet
from a height h. The time t taken by the packet in reaching
the ground will be
(a)  
2g
h
æö
ç÷
èø
(b)
2u
g
æö
ç÷
èø
(c)
2
h
g
æö
ç÷
èø
(d)
2h
g
æö
ç÷
èø
DPP/ P 04
3
Q.15 T wo trains, each 50 m long are travelling in opposite direction
with velocity 10 m/s and 15 m/s. The time of crossing is
(a) 2s (b) 4s
(c)
23s
(d) 43s
Q.16 A train of 150 metre length is going towards north direction
at a speed of 10 m/s. A parrot flies at the speed of 5 m/s
towards south direction parallel to the railway track. The
time taken by the parrot to cross the train is
(a) 12 sec (b) 8 sec
(c) 15 sec (d) 10 sec
Q.17 The distance between two particles is decreasing at the rate
of 6 m/sec. If these particles travel with same speeds and in
the same direction, then the separation increase at the rate
of 4 m/s. The particles have speeds as
(a) 5 m/sec; 1 m/sec (b) 4 m/sec; 1 m/sec
(c) 4 m/sec; 2 m/sec (d) 5 m/sec; 2 m/sec
Q.18 A train is moving towards east and a car is along north, both
with same speed. The observed direction of car to the
passenger in the train is
(a) East-north direction (b) West-north direction
(c) South-east direction (d) None of these
Q.19 An express train is moving with a velocity v
1
. Its driver
finds another train is moving on the same track in the same
direction with velocity v
2
. To escape collision, driver applies
a retardation a on the train, the minimum time of escaping
collision will be
(a)
12
-
=
vv
t
a
(b)
22
12
1
2
-
=
vv
t
(c) Both (a) and (b) (d) None of these
DIRECTIONS (Q.20-Q.22) : In the following questions, more
than one of the answers  given are correct. Select the correct
answers and mark it according to the following codes:
Codes :
(a) 1, 2 and 3 are correct ( b) 1 and 2 are correct
(c) 2 and 4 are correct ( d) 1 and 3 are correct
Q.20 Two particles move simultaneously from two points A and B,
300m apart. The particle at A, starts towards B with a velocity
of 25 m/s and that at B, moves normal to the former with a
velocity of 20 m/s.
(1) The relative velocity of the particle at A, w .r.t. that at B is
32.02 m/s
(2) The relative velocity of the particle at A, w .r.t. that at B is
12.04 m/s
(3) They are closest to each other after 7.32 sec.
(4) They are closest to each other after 4.25 sec.
Q.21 A plane is to fly due north. The speed of the plane relative
to the air is 200 km/h, and the wind is blowing from west
to east at 90 km/h.
(1) The plane should head in a direction of sin
–1
 (0.45)
(2) The plane should head in a direction of sin
–1
 (0.60)
(3) The relative velocity of plane w .r.t. ground is 179 km/h
(4) The relative velocity of plane w .r.t. ground is 149 km/h
Q.22 From the top of a multi-storeyed building 40m tall, a boy
projects a stone vertically upwards with an initial velocity
of 10 ms
–1
 such that it eventually falls to the ground.
(1) After 4 s the stone will strike the ground
(2) After 2 s the stone will pass through the point from
where it was projected
(3) Its velocity when it strikes the ground is 30 m/s
(4) Its velocity when it strikes the ground is 40 m/s
DIRECTIONS (Q.23-Q.25) : Read the passage given below
and answer the questions that follows :
When an airplane flies, its total velocity with respect to the
ground is v
total
 = v
plane
 + v
wind
,
where v
plane
 denotes the plane’s velocity through motionless air,
and v
wind
 denotes the wind’s velocity .  Crucially , all the quantities
in this equation are vectors.  The magnitude of a velocity vector
is often called the “speed.”
Consider an airplane whose speed through motionless air is 100
meters per second (m/s).  To reach its destination, the plane must
fly east.
The “heading” of a plane is in the direction in which the nose of
the plane points. So, it is the direction in which the engines propel
the plane.
4
DPP/ P 04
Q.23 If the plane has an eastward heading, and a 20 m/s wind
blows towards the southwest, then the plane’s speed is –
(a) 80 m/s
(b) more than 80 m/s but less than 100 m/s
(c) 100 m/s
(d) more than 100 m/s
Q.24 The pilot maintains an eastward heading while a 20 m/s
wind blows northward. The plane’s velocity is deflected
from due east by what angle?
(a)
sin
-1
20
100
(b)
cos
-1
20
100
(c)
tan
-1
20
100
(d) none
Q.25 Let f denote the answer of above question. The plane has
what speed with respect to the ground ?
(a) (100 m/s) sin f (b) (100 m/s) cos f
(c)
100m/s
sin f
(d)
100m/s
cos f
DIRECTIONS (Qs. 26-Q.28) : Each of these questions
contains two statements: Statement-1 (Assertion) and
Statement-2 (Reason). Each of these questions has four
alternative choices, only one of which is the correct answer.
You have to select the correct choice.
(a) Statement-1 is True, Statement-2 is True; Statement-2 is a
correct explanation for  Statement-1.
(b) Statement-1 is True, Statement-2 is True; Statement-2 is NOT
a correct explanation for Statement-1.
(c) Statement -1 is False, Statement-2 is True.
(d) Statement -1 is True, Statement-2 is False.
Q.26 Statement-1 : The magnitude of velocity of two boats
relative to river is same. Both boats start simultaneously
from same point on the bank may reach opposite bank
simultaneously moving along different paths.
Statement-2 : For boats to cross the river in same time.
The component of their velocity relative to river in
direction normal to flow should be same.
Q.27Statement-1 : The acceleration of a body of mass 2 kg
thrown vertically upwards is always constant.
Statement-2 : A body of all mass group travels under
constant acceleration when only gravity acts on it.
Q.28 Statement-1 : The velocity of a body A relative to the body
B is the sum of the velocities of bodies A and B if both
travel  in opposite direction on a straight line.
Statement-2 : The velocity of a body A relative to the body
B is the difference of the velocities of bodies A and B if
both travel in opposite direction on a straight line.