Question 1 :
An iron ball and a wooden ball of the same radius are released from a height H in vacuum. The times taken by both of them of reach the ground are
Question 2 :
A boy can throw a stone up to a maximum height of 10 m. The maximum horizontal distance that boy throw the same stone up will be
Question 3 :
When two bodies move uniformly towards each other, the distance decreases by $6ms^{-1}$.If both bodies move in the same direction with the same speed as above the distance between them increases by $4ms^{-1}$. Then the speed of the two bodies are
Question 4 :
A block of mass $2\ kg$ starts moving with initial speed of $10\ m/s$ and accelerates at $-2 m/s^2$. How much time will pass until it comes to rest? 
Question 5 :
Two particles A and B having different masses are projected from a tower with same speed. A is projected vertically upward and B vertically downward. On reaching the ground.<br>
Question 7 :
Two cars are moving in the same direction with the same speed $30km/hr$. They are separated by a distance of $5km$ the speed of a car moving in the opposite direction if it meets these two cars at interval of 4 minutes, will be:
Question 8 :
From a building two balls A and B are thrown such that A is thrown upwards and B downwards (both vertically). If $\displaystyle { v }_{ A }$ and $\displaystyle { v }_{ B }$ are their respective velocities on reaching the ground, then
Question 9 :
A stone is thrown upwards with a velocity $50 mg^{-1}$. Another stone is simultaneously thrown downwards from the same location with a velocity $50 ms^{-1}$. When the first stone is at the highest point, the relative velocity of the second stone w.r.t. the first stone is:
Question 10 :
A ball is dropped off a high building and strikes the ground with an impact velocity of 30 m/s. Calculate the height of building :<br/>
Question 11 :
At an airport, a bored child starts to walk backwards on a moving platform. The child accelerates relative to the platform with $a=-0.5{m}/{{s}^{2}}$ relative to the platform.<br>The platform moves with a constant speed $v=+1.0{m}/{s}$ relative to the stationary floor.<br>In $4.0$ seconds, how much will the child have been displaced relative to the floor?
Question 12 :
If two particles of masses $3kg$ and $6kg$ which are at rest are separated by a distance of $15m$. The two particles are moving towards each other under a mutual force of attraction. Then the ratio of distances travelled by the particles before collision is <br/>
Question 13 :
A ball is thrown vertically upward with speed $10$ m/s and it returns to the ground with speed $8$ m/s. A constant air resistance acts. The maximum height attained by the ball is?
Question 14 :
A stone is dropped from a building and $2$ seconds later another stone is dropped. How far apart are these two stones by the time the first one reaches a speed of $30m{ s }^{ -1 }$? (Take $g=10m{ s }^{ -2 }$)
Question 15 :
A body is thrown vertically upwards and rises to a height of $10 m$. The time taken by the body to reach the highest point is
Question 16 :
Two particles A and B having different masses are projected from a tower with same speed. A is projected vertically upward and B vertically downward. On reaching the ground.<br>
Question 17 :
Consider a car moving on a straight roads with a speed of $ 100 m/s$. The distance at which car can be stopped is $\left[ { \mu }_{ x }=0.5 \right] $
Question 18 :
A ball of mass m is dropped from a high building and strikes the ground $ 4 $ seconds later. Calculate the height of the building.
Question 19 :
If an iron ball and a wooden ball of the same radius are released from a height h in vaccum then time taken by both of them to reach ground will be:-
Question 20 :
A ball is thrown upward with a velocity of 100m/s it will reach the ground after :-
Question 21 :
A body projected vertically upwards with a velocity u return to the starting point in 4second .If $g=10m^{-2}$ the value of u is $(m/s)$:-
Question 22 :
When a man stands on a moving escalator he goes up in $50\ sec.$ and when he walks up the moving escalator he goes up in $30\ sec.$ Then the man walks up the stationary escalator in a time of $----sec$
Question 23 :
A passenger in a moving train tosses a coin. If the coin falls behind him, the train must be moving with
Question 24 :
A helicopter is flying south with a speed of $50\, km h^{-1}$. A train is moving at the same speed towards east. The relative velocity of the helicopter as seen by the passengers in the train will be towards
Question 25 :
A bus moving with a speed of $10m/s$ on a straight road. A scooterist wishes to overtake the bus in $100s$. If the bus is at a distance of $1km$ from the scooterist, with what speed should the scooterist chase the bus?
Question 26 :
If a body is thrown up with an initial velocity u and covers a maximum height of h, then h is equal to
Question 27 :
A toy rocket is launched straight up. At the exact top of its flight path, which of the following is true?
Question 28 :
The acceleration of a body projected upwards with a certain velocity is equal to :
Question 29 :
A block is released from rest at the top of a frictionless inclined plane 16 m long. It reaches the bottom 4 sec later. A second block is projected up the plane from the bottom at the instant the block is released in such a way that it returns to the bottom simultaneously with first block. The acceleration of each block on the incline is
Question 30 :
A ball is thrown vertically up. If the ball reached at maximum height in $3s$. Assume air resistance is negligible. The magnitude of the acceleration of the ball at the instant it reaches its maximum height is most nearly:
Question 31 :
A stone falls from a balloon that is descending at a uniform rate of $12ms^{-1}$. The displacement of the stone from the point of release after 10sec is :-
Question 32 :
A stone is thrown upwards and it rises to a height of $200 m$. The relative velocity of the stone with respect to the earth will be maximum at :
Question 33 :
A bowling ball is rolling westward and slowing down as it approaches the end of the alley. The direction of the bowling ball's acceleration is :
Question 34 :
A purple car is moving three times as fast as a yellow car. Each car slows down to a stop with the same constant acceleration.<br>How much more distance is required for the purple car to stop?
Question 35 :
Two bodies of masses $20 kg$ and $15 kg$ are dropped from the top of a building. At any instant during the fall, which of the following properties that both the bodies posses is equal in magnitude?
Question 36 :
Three bodies $A, B$ and $C$ are moving in a straight line in the same direction such that relative velocity of $A$ w.r.t $B$ is $2m/s$, relative velocity of $B$ w.r.t $C$ is $5m/s$.<br/>Find the relative velocity of $C$ w.r.t $A$. 
Question 37 :
How do the directions of velocity and acceleration act when brakes are applied to a moving cycle?
Question 38 :
The same retarding force is applied to stop a train. If the speed is doubled, then the distance will be
Question 39 :
If a ball is thrown vertically upwards with 40 m/s its velocity after two second will be:-
Question 40 : <p>A sign convention is used, the positive direction for position, velocity and acceleration is upward. A ball of mass m is thrown upward with velocity $V$ and caught during returning. Identify the signs of position, velocity and acceleration during ascending part of the trajectory.<br/></p><table class="wysiwyg-table"><tbody><tr><td></td><td>Position</td><td>Velocity</td><td>Acceleration</td></tr><tr><td>(A)</td><td>Positive</td><td>Positive</td><td>Positive</td></tr><tr><td>(B)</td><td>Positive</td><td>Positive</td><td>Negative</td></tr><tr><td>(C)</td><td>Positive</td><td>Negative</td><td>Negative</td></tr><tr><td>(D)</td><td>Negative</td><td>Positive</td><td>Negative</td></tr><tr><td>(E)</td><td>Negative</td><td>Negative</td><td>Negative</td></tr></tbody></table>
Question 41 :
Consider a car traveling west at 60 MPH. The passenger throws a ball in the same direction the car is traveling. If the passenger clocks the speed of the ball at 40 MPH, what is the speed of the ball relative to the road?<br>
Question 42 :
The acceleration of a body projected upwards with a certain velocity is
Question 43 :
Two stones are dropped from the top of a tower at half a second apart. The time after dropping the first stone at which the distance between the two stones is 20 m is $(g = 10 ms^{-2})$
Question 44 :
A motorcycle is moving with a velocity 80km/hr ahead of a car moving with a velocity of 65 km/hr in the same direction. What is the relative velocity of the motorcycle with respect to the car :-
Question 45 :
A ball is released from the top of a tower of height h metres. It takes T seconds to reach the ground. What is the position of the ball in ${ T }/{ 3 }$ seconds?
Question 46 :
A body is thrown vertically upwards and rises to a height of 10 m. The velocity with which the body was thrown upwards is $\displaystyle \left( g=9.8{ m }/{ { s }^{ 2 } } \right) $
Question 47 :
Acceleration of a body projected upwards with a certain velocity is
Question 48 :
A body falls from a height $h=200\ m$.The ratio of distance travelled in each $2 sec$ during $t=0$ to $t=6\ sec$ of the journey is
Question 49 :
A body thrown up with a finite speed is caught back after 4 sec. The speed of the body with which it is thrown up is
Question 50 :
A particle experiences constant acceleration for $20 s$ after starting from rest. If it travels a distance ${X}_{1}$, in the first $10 s$ and distance ${X}_{2}$, in the remaining $10 s$, then which of the following is true ?
Question 51 :
A body falls freely from a tower and travels a distance of $40\ m$ in its last two seconds. The height of the tower is (take $g = 10\ m/s^{2})$.
Question 52 :
Assertion - The sound emitted by the source travels in all directions.<br>Reason - The relative velocity of sound with respect to the observer is the sum of velocity of sound and velocity of observer.<br>
Question 53 :
A body starts with an initial velocity of $15 \,m / s.$ If the acceleration of the body is $4 \,m / s^2,$ its velocity after $8$ seconds will be-
Question 54 :
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?<br/>
Question 55 :
A lift is moving down with acceleration $a$. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively.
Question 56 :
The position of a body is given as a function of time by the relation, $x = 2t^{3}-6t^{2}+12t+6$. The acceleration of the body is zero, after a time
Question 57 :
A body is released from the top of the tower of height $H$. It takes $t$ time to reach the ground. The position of body $\displaystyle \dfrac{t}{2}$ time after release will be<br/>
Question 58 :
An airliner reaches its takeoff speed of $163 mph$ in $36.2 s$. What is the magnitude of its average acceleration. (in $m/s^2$)
Question 59 :
A jet airplane is travelling at a speed of $500$ km/h ejects its products of combustion with a speed of $1500$ km/h relative to the jet plane. The speed of the latter with respect to an observer on the ground is:
Question 60 :
Three ships A, B & C are in motion. The motion of A as seen by B is with speed $v$ towards north-east. The motion of B as seen by C is speed $v$ towards the north-west. Then as seen by A, C will be moving towards
Question 61 :
A particle is falling freely under gravity. In first $t$ second it covers distance $\displaystyle x_{1}$ and in the next $t$ second it covers distance $\displaystyle x_{2},$ then t is given by<br/>
Question 62 :
A stone is dropped from the $25^{th}$ storey of a multistoried building and it reaches the ground in 5 s. In the first second, it passes through how many storeys of the building? $(g=10ms^{-2}).$
Question 63 :
Initially car A is 21 m ahead of car B. Both start moving at time t=0 in same direction along straight line. if A is moving with constant velocity 20 m/s and B starts from rest with an acceleration ${ 2m/s }^{ 2 }$ towards A, then the time when car B will catch the car A is
Question 64 :
The position of a particle moving in the x-y plane at any time $t$ is given by : $x=(3{t}^{3}-6t)$ metres; $y=({t}^{2}-2t)$ metres. Select the correct statement.
Question 65 :
A ball is released from the top of height 'h' metres. It takes 't' seconds to reach the ground. Where is the ball at the time t/2 s?
Question 66 :
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 $1$ m  after $n$ seconds from the start of the first body, then $n$ is equal to:
Question 67 : <p>A ball is thrown vertically upwards from the top of a tower with a velocity of 10 m/sec. If the ball falls on the ground after 5 seconds, the height of the tower will be $\left( {{\text{use}}\;g = 10m/{s^2}} \right)$</p>
Question 68 :
A body falling from the rest has a velocity v after it fall through a height h. The distance it has to fall down further for its velocity to become double, will be
Question 69 :
A ball of mass $m$ is thrown vertically upwards. Another ball of mass $2m$ is thrown simultaneously at an angle $\theta$ with horizontal. Both of them hit the ground at the same time when thrown from the same height. The heights attained by the two are in the ratio ?
Question 70 :
An engine of a vehicle can produce a maximum acceleration of $4 ms^{-2}$. Its brakes can produce a maximum retardation of $6ms^{-2}$. The minimum time at which it can cover a distance of $3 \,km$ is:
Question 71 :
A particle is projected vertically upwards and it attains maximum height $H$. If the ratio of times to attain height $h(h < H)$ is $1/3$, then $h$ equals
Question 72 :
An astronaut jumps from an airplane. After he had fallen $40 m$, then his parachute opens. Now he falls with a retardation of $2 m/s^2$ and reaches the earth with a velocity of $3.0 m/s$. What was the height of the aeroplane? (in m)
Question 73 :
In the free fall, ......... energy of the man is converted into ......... energy. 
Question 74 :
An object A is dropped from rest from the top of a <b>30</b> <b>m</b> high building and at the same moment another object B is projected vertically upwards with an initial speed of <b>15 m/s</b> from the base of the building. Mass of the object A is <b>2 kg</b> while mass of the object B is <b>4</b> <b>kg</b>. The maximum height above the ground level attained by the center of mass of the A and B system is $( take\;g= 10\;m/s^2 ):$
Question 75 :
The co-ordinates of a particle restricted to move in a plane is given by<br/>$X = 6\ cos\pi t$<br/>$y= 1-4cos2\ \pi t$<br/>The magnitude of acceleration of particle at $t=1.5\ s$ is (where $x$ and $y$ are in meter and $t$ is in seconds)<br/><br/>
Question 76 :
A body starts from rest and is uniformly acclerated for $30 s$. The distance travelled in the first $10 s$ is $x_1$, next 10 s is $x_2$ and the last 10 s is $x_3$. Then $x_1\, :\, x_2\, :\, x_3$ is the same as
Question 77 :
The same retarding force is applied to stop a train, if the speed is doubled then the stopping distance will be <br/>
Question 78 :
The equation of motion of  a particle started at t=0, is given by $ y=5 sin (20 t+\dfrac{\pi}{3})cm$. The least time after which acceleration becomes zero is:
Question 79 :
Consider a jet traveling at 1000 km/hr. If the jet shoots a laser in the same direction it is traveling, how fast will the laser be traveling relative to the jet?<br>
Question 80 :
An electric motor operates on a 50 volt supply and a current of 12A. If the efficiency of the motor is 30%, what is the resistance of the winding of the motor   
Question 81 :
A proton in a uniform electric field moves along a straight line with constant acceleration starting from rest. If it attains a velocity $4\times 10^3$ $km/s$ at a distance of $2\;cm$, the time required to reach the given velocity is :<br/>
Question 82 :
A car moving on a straight path covers a distance of 1 km due east in 100 s. What is the velocity of car ?
Question 83 :
A body is thrown vertically upwards with a velocity u . Find the true statement from the following
Question 84 :
A bus begins to move with an acceleration of $\dfrac{1}{2} \,m/s^2$. A person who is $40 \,m$ behind the bus, runs at a rate of $7 \,m/s$. Find the time taken by the person to catch the bus.
Question 85 :
A car accelerating from rest at $2.0\ m/s^{2}$ for $5\ s$
Question 86 :
A boat is moving with velocity $3\hat{i}+4\hat{j}$ with respect to ground. The water in the river is moving with velocity $-3\hat{i}-4\hat{j}$ with respect to ground. The relative velocity of the boat with respect to water is
Question 87 :
A fire extinguishing hose pipe disposes watch at a speed of 10 m/s to put off fire on a building. Assuming safe distance from the building on ground is 5 m, What is the maximum height at which water strikes building?
Question 88 :
Assertion: A person seated in a moving train is at rest with respect to another train moving in the opposite direction.
Reason: If the train covers equal displacement in equal intervals of time then it moves with uniform acceleration.
Question 89 :
The function which represents the height, $h(t)$, of a ball t seconds after it is kicked into the air is<br/>$h(t)\, =\, - 16t^2\, +\, 64t$.<br/>What does $t$ represent if $h(t)$ is zero ?
Question 90 :
A car travels a distance 100 m with a constant acceleration and average velocity of $20\, ms^{-1}$. The final velocity acquired by the car is $25\, ms^{-1}$. Find the acceleration of the car.
Question 91 :
A bullet penetrates a distance d of a plank. If the initial momentum of the bullet is doubled, the distance penetrated will be
Question 92 :
Two cars X and Y start off to a race on a straight path with initial velocities of 8 m/s and 5 m/s respectively. Car X moves with uniform acceleration of $1{ m/s }^{ 2 }$ and car Y moves with uniform acceleration of $1.1 { m/s }^{ 2 }$. If both the cars reach the winning post together find the length of the track.
Question 93 :
A ball is thrown vertically upwards from the top of a tower with an initial velocity of $19.6 m {s}^{-1}$. The ball reaches the ground after $5 s$. Calculate :$(i)$ the height of the tower, $(ii)$ the velocity of ball on reaching the ground. Take $g=9.8 m {s}^{-2}$.
Question 94 :
Assertion: A person seated in a moving train is a rest with respect to another train moving in the opposite direction.
Reason: If the train covers equal displacement in equal intervals of time then it moves with uniform acceleration.
Question 95 :
An object is dropped from a moving vehicle. Identify which of the following statements is not true?<br/>I. The velocity of the object changes.<br/>II. The acceleration of the object changes.<br/>III. The direction of motion of the object changes
Question 96 :
A stone thrown vertically upwards with an initial velocity $u$ from the top of a tower, reaches the ground with a velocity of 3$ u$. The height of the tower is :
Question 97 :
A particle having initial velocity $u$ moves with a constant acceleration $a$ for a time $t$. Find the displacement of the particle in the last one second. <br/><br/>
Question 98 :
A nail of mass $'m_1'$ kg is being hammered by a hammer of mass $'m_2'$ kg with a velocity of 'v' m s$^{-1}$ such that the nail drives by 's' m into a wall. Find the average resistance offered by the wall to the penetration of nail.<br>
Question 99 :
A ball is thrown upwards with a velocity of $25 m/s$. What is the time taken by the ball to return to the thrower ($g=10\:m/s^2$)
Question 100 :
Free fall of an object in vacuum is a case of motion with :
Question 101 :
A ball is thrown vertically upwards with a velocity of $10 ms^-1$. IT returns to the ground with a velocity of$ 9 ms^-1$. If $g = 9.8 ms^-2$, then the maximum height attained by the ball is nearly ( assume a resistance to be uniform)
Question 102 :
A machine gun is mounted on a $2000 kg $ vehicle on a horizontal smooth road (friction negligible). The gun fires $10 $ bullets per sec with a velocity of $500 m/s $ . If the mass of each bullet be $10 g $ , what is the acceleration produced in the vehicle?
Question 103 :
A swimmer is capable of swimming $1.65$ $ms^{-1}$ in still water. If she swims directly across a $180$m wide river whose current is $0.85$ m/s, how far downstream(from a point opposite her standing point) will she reach?
Question 104 :
A stone thrown upwards with speed $u$ attains maximum height $h$. Another stone thrown upwards from the same point with sapped $2u$ attains maximum height $H$. What is the relation between $h$ and $H$?
Question 105 :
A swimmer's speed in the direction of flow of river is $ 16 kmh^{-1} $ . Against the direction of flow of river, the swimmer's speed is $8 kmh^{-1} $ Calculate the swimmer's speed in still water and the velocity of flow of the river.
Question 106 :
A truck travelling due to north at $30\ m/s$ turns west and travels at the same speed, then the change in velocity is :
Question 107 :
Two particles $A$ and $B$ start moving with velocities $20\ m/s$ and $30\sqrt{2}\ m/s$ along $x-axis$ and at an angle $45^{o}$ with $x-$axis respectively in $xy-plane$ from origin. The relative velocity of $B$ w.r.t. $A$
Question 108 :
Two parallel rail tracks run north-south. Train $A$ moves north with a speed of $54\ km{h}^{-1}$ and train $B$ moves south with a speed of $90\ km{h}^{-1}$. The relative speed of $B$ with respect to $A$ is:
Question 109 :
A stone A is dropped from a height h above the ground. A second stone B is simultaneously thrown vertically up from a point on the ground with velocity v. The line of motion of both the stones is same. The value of v which would enable the stone B to meet the stone A midway ( at midpoint) between their initial position is:
Question 110 :
The wheels of an airplane are set into rotation just before landing so that the wheels do not slip on the ground. If the airplane is travelling in the east direction, what should be the direction of angular velocity vector of the wheels?
Question 111 :
Consider a collection of a large number of particles each with speed $v$. The direction of velocity is randomly distributed in the collection. The magnitude of the relative velocity between a pair of particles averaged over all the pairs in the collection is <br/>
Question 112 :
A jet airplane travelling from east to west at a speed of $500\,km\ h^{-1}$ eject out gases of combustion at a speed of $1500\ km\ h^{-1}$ with respect to the jet plane. What is the velocity of the gases with respect to an observer on the ground?
Question 113 :
A "moving sidewalk" in a busy airport terminal moves $1 m/s$ and is $200 m$ long. A passenger steps onto one end and walks, in the same direction as the sidewalk is moving, at a rate of $2.0 m/s$ relative to the moving sidewalk. How much time does it take the passenger to reach the opposite end of the walkway? (in seconds)
Question 114 :
A man of $80 kg$ attempts to jump from a small boat of mass $40 kg$ on to the shore. He can generate a relative velocity of $6 m/s $ between himself and boat. His velocity towards the shore is:
Question 115 :
If the plane has an eastward heading, and a $20 m/s$ wind blow towards the southwest, then the plane's speed is-
Question 116 :
Four persons A, B, C and D at the corners of an square of side $X$ move at a constant speed $V$. Each person maintains a direction towards the person at the next corner. The time, the persons take to meet each other is
Question 117 :
There is a regular bus service between towns A and B, with a bus leaving towns A and B every $T$ minutes. A cyclist moving with a speed of $20\ km h^{-1}$ in the direction A to B notices that a bus goes past him every $18  mins$ in his direction and every $6  mins$ in the opposite direction. What is the period $T$ of bus service?
Question 118 :
A juggler tosses a ball up in the air with speed $u$ . At the instant it reaches its maximum height $H$ , he tosses up a second ball with the same initial speed. The two balls will collide at a height.
Question 119 :
Two bodies are thrown vertically upward, with the same initial velocity of $98\ m/s$ but $4\ sec$ apart. How long after the first one is thrown when they meet ?
Question 120 :
A train is moving at a constant speed V when its driver observes another train in front of him on the same track and moving in the same direction with constant speed v. If the distance between the trains is x, then what should be the minimum retardation of the train so as to avoid collision?
Question 121 :
Two particles A and B are shot from the same height at $t=0$ in opposite directions with horizontal velocities $3m/s$ and $4m/s$ respectively. If they are subjected to the same vertical acceleration due to gravity ($g=9.8m/{s}^{2}$). the distance between them when their velocity vectors become mutually perpendicular is:
Question 122 :
A bus is moving with a speed of $10ms^{-1}$ on a straight road. A scooterist wishes to overtake the bus in 100s. If the bus is at a distance of 1 km from the scooterist, with what speed should the scooterist chase the bus ?<br>
Question 123 :
A stone is dropped from a height h. Simultaneously, another stone is thrown up from the ground which reaches a height of $4h$. The two stones cross each other after time
Question 124 :
The driver of a train moving with a constant speed $v_1$ along a straight track sights another train at a distance d ahead of him on the same track moving in the same direction with a constant speed $v_2$. He at once applies the brakes and gives his train a constant retardation f. There will be a collision of the trains if:<br>
Question 125 :
A police party is moving in a jeep at a constant speed $V$. They saw a thief at a distance $x$ on a motorcycle which is at rest. The moment the police saw the thief, the thief started at constant acceleration $a$. Which of the following relations is true if the police is able to catch the thief?<br/>
Question 126 :
A person walk up a stalled 15 m long escalator in 90 s. When standing on the same escalator, now moving, the person is carried up in 60 s. How much time would it take that person to walk up the moving escalator? Does the answer depend on the length of the escalator?<br>
Question 127 :
Two trains are moving with velocities $\displaystyle v_{1}=10\ ms^{-1}$ and $\displaystyle v_{2}=20\ ms^{-1}$ on the same track in opposite directions. After the application of brakes if their retarding rates are $\displaystyle a_{1}=2\ ms^{-2}$ and $\displaystyle a_{1}=1\ ms^{-2}$ respectively, then the minimum distance of separation between the trains to avoid collision is<br>
Question 128 :
Assertion: Displacement-time equation of two particles moving in a straight line are, $\displaystyle s_{1}=2t-4t^{2}$ and $\displaystyle s_{2}=2t+4t^{2}.$ Relative velocity between the two will go on increasing.
Reason: If velocity and acceleration are of same sign then speed will increase.
Question 129 :
The time in which the ball strikes the floor of elevator is given by<br>
Question 130 :
A thief in a stolen car passes through a police check post at his top speed of $\displaystyle 90\ kmh^{-1}.$ A motorcycle cop, reacting after $2\ s$, accelerates from rest at $\displaystyle 5\ ms^{-2}.$ His top speed being $\displaystyle 108\ kmh^{-1}.$ Find the maximum separation between policemen and thief.<br/>
Question 131 :
The driver of a train moving with a speed $v_{ 1 }$ sights another train at a distance $s$, ahead of him moving in the same direction with a slower speed $v_{ 2 }$. He applies the brakes and gives a constant deceleration $a$ to his train. For no collision, $s$ is<br>
Question 132 :
Two persons A and B running on a straight track in the same direction observe a car. A says that the car is moving in east direction and B says that the car is moving in north direction. They contradict the direction but say that magnitude is same. If the speed of B is double that of the speed of A, then the true direction of the car will be<br/>
Question 133 :
Two particles move in space with nonzero initial relative velocity and nonzero constant relative acceleration. Then :<br/>
Question 134 :
A particle is thrown up inside a stationary lift of sufficient height. The time of flight is $T$. Now it is thrown again with same initial speed $v_{0}$ with respect to lift. At the time of second throw, lift is moving up with speed $v_{0}$ and uniform acceleration $g$ upward (the acceleration due to gravity). The new time of flight is :<br/>
Question 135 :
N particles moving in a straight line have initial velocities of 1, 2, 3, ........... N m/s and accelerations of 1, 2, 3, ...... N m/s$^2$ respectively. If the initial spacing between any two consecutive particles is same then, select the correct alternative(s).<br/>
Question 136 :
distance travelled by the ball upto that instant, when lift and ball were of same height from ground Take $\displaystyle g= 10m/s^{2}$
Question 137 :
The driver of an express train travelling at a speed of $v_{1}$ sees on the same track at distance $d$ in front of him a goods train travelling in the same direction at a speed $v_{2}$ such that $v_1>v_2$. Immediately he applies brakes to his express train producing retardation $a$ to avoid collision. Then
Question 138 :
If six persons are at the corners of a regular hexagon of side $X$ move at a constant speed $V$. Each person maintains a direction towards the person at the next corner. The time, the persons will take to meet each other is
Question 139 :
The maximum height reached by ball, as measured from the ground would be<br>
Question 140 :
Two particles $P$ and $Q$ move in a straight line $AB$ towards each other. $P$ starts from $A$ with velocity $u_{1}$, and an acceleration $a_{1}$, $Q$ starts from $B$ with velocity $u_{2}$ and acceleration $a_{2}$.They pass each other at the midpoint of $AB$ and arrive at the other ends of $AB$ with equal <i></i>velocities
Question 141 :
Displacement of ball with respect to ground during its flight would be<br>
Question 142 :
The maximum separation between the floor of elevator and the ball during its flight would be <br>
Question 143 :
A man is driving at the speed $40 mph$ when he see an obstacle at distance $300 ft$ ahead of his position. The driver applies the brakes and decelerates at $10 ft/s^2$.How far from the obstacle will the driver be when he finally stops? (in metres)
Question 144 :
A man is driving at the speed $40 mph$ when he see an obstacle at distance $300 ft$ ahead of his position. The driver applies the brakes and decelerates at $10 ft/s^2$ How long does it take him to stop the vehicle? (in s)
Question 145 :
Ima Hurryin is approaching a stoplight moving with a velocity of $+30.0 m/s$. The light turns yellow, and Ima applies the brakes and skids to a stop. If Ima's acceleration is $-8.00 m/s^2$, then determine the displacement of the car during the skidding process. (Note that the direction of the velocity and the acceleration vectors are denoted by a $+$ and a $-$ sign.)
Question 146 :
A bullet travelling horizontally loses ${\dfrac{1}{20}^{th}}$ of its velocity while piercing a wooden plank. Number of such planks required to stop the bullet is:
Question 147 :
A car traveling at a speed $ 30 km h^{-1}$ is brought to a halt in 8 m by applying breaks. If the same car is traveling at $60 km h^{-1}$, it can be brought to a halt with the same breaking power in :
Question 148 :
A particle starts from the origin with a velocity of 10 m/s and moves with a constant acceleration till the velocity increases to 50 m/s. At that instant, the acceleration is suddenly reversed. What will be the velocity of the particle, when it returns to the starting point?
Question 149 :
A particle moves in circle of radius $9m$. Its linear speed is given by $v=3t$. What is the net acceleration of the partical at $T=2\ sec$.
Question 150 :
Two cars 1 & 2 starting from rest are moving with speeds $V_1 $ and $V_2 m/s (V_1 > V_2),$ car 2 is ahead of car '1' by 'S' metres when the driver of car '1' sees car '2'. What minimum retardation should be given to car '1' to avoid collision.
