Kinematics Questions and Answers

1 Rain is falling vertically with a speed of 30 m s A woman rides a bicycle with a speed of 12 m s in east to west direction In which direction she should hold her umbrella a At an angle of tan with the vertical towards the east b At angle of tan the west 3 with the vertical towards c At angle of tan the east with the vertical towards d At angle of tan with the vertical towards the west 2 A river is flowing from west to east with a speed

1 r 36 In the question number 35 the acceleration of the particle at t 1 s is a 2 ms c 4 ms 37 Ifr b 2 ms d 4 ms

eger Type A particle is projected vertically upwards with speed u in a medium in which the resistance motion is proportional to square of speed Initially net force is double to its weight The time ascent and maximum height are kru pu log 2 The values of k and p are 4 g 4g

7 If a body is projected with an angle 8 to the horizontal then a its velocity is always perpendicular to its acceleration b its velocity becomes zero at its maximum height c its velocity makes zero angle with the horizontal at its maximum height d the body just before hitting the ground the direction of velocity coincides with the acceleration 18 Two particles are proiected simultaneously in the

Three particles A B and C start moving from the vertices of an equilateral triangle of side length with speed u each such that A moves towards B B towards C and C towards A Find the initial angular velocity of B with respect to A 3u 21 2 u 2l

a Show that the sum of the potential energy and kinetic energy of a body falling freely from a certain height is always constant b What work is performed in dragging a block 50m horizontally when a 50N force is applied by a rope making an angle 60 with the ground

Ball A is thrown upwards with a speed of 35 m s from the ground while at the same time another ball B is dropped from a height of 100 m with a speed of 10 m s along the same straightline Find the height from the ground where the two balls meet Take g 10 m s2 OA 45 m OB 72 m OC 30 m W

Motion in a Plane MOTION IN A PLANE WITH CONSTANT ACCELERATION 38 A particle starts from origin at t 0 with a velocity sims and moves in x y plane under the action of a force which produces a constant acceleration of

45 A bomb is released by a horizontal flying aeroplane The trajectory of the bomb is a a parabola c a circle b a straight line d a hyperbola 46 In case of a projectile motion what is the angle

45 A socket is fired upward from the earthle Surbare such that it creates acceleration of 19 6 ms gf after be its engine is switched off the maximum height of the rocket ferom earth s surface would be Ans Msing V U we find a t Here V 0 So v at 0 m 19 6 5 0 1 98 0 98m e 2 2 Qal v u 2x19 6xS 98 S 98X9849

mtG Objective NCERT Physics Ocket 32 Four girls skating on circular ice I that The nary ground of radius 200 m start from apoint Pon the edge of the ground and reach a point Q diametrically opposite to P following different paths as shown in figure For which girl displacement is equal AC

2 A river is flowing from west to east with a speed 5 ms A swimmer can swim in still water at a speed of 10 ms If he wants to start from point A on south bank and reach opposite point B on north bank in what direction should he swim a 30 east of north b 60 east of north c 30 west of north d 60 west of north A girl riding a bicycle with a speed of 5 ms towards 5ms

M 2031 3mys Lo A 30 Figure shows a fixed wedge block with its inclined surface at 30 From point A on the inclined surface a particle is projected at 3m s in the plane of inclined at an angle of 60 to the line parallel to its base Find the speed of particle after 2 seconds 8 60 IDM

A particle travels half the distance with a velocity of 6 ms The remaining half distance is covered with a velocity of 4 ms 1 for half the time and with a velocity of 8 ms 1 for the rest of the half time What is the velocity of the particle averaged over the whole time of motion A 9 ms 1 B 6 ms 1 C 5 35 ms 1 D 5 ms 1

The graph of displacement time for a body travelling in a straight line is given we can conclude that A B di x V T A The velocity is constant B The velocity increases uniformly C The body is subjected to acceleration from O to A D The velocity of the body at A is zero

7 If x 5t 3t and y 4t are the x and y co ordinates of a particle at any time t second where x and y are in metre then the acceleration of the particle a is zero throughout its motion b is a constant throughout its motion c depends only on its y component d varies along both x and y direction

c 2 10 8 34 For any arbitrary motion in space which of the following relations is true a Faverage F 1 F 1 b average c v t v 0 t d F t F 0 v 0 t at The average stands for average of the quantity over the time interval t to t particle is given by

Two persons A B are throwing ball of 200 g on wall as shown in figure Balls strike wall perpendicularly at same point height 2m from ground Ball strike wall elastically at same time and returns back to A B at same time They again repeat the same What is the average force on wall take g 10 m s B O 5m 1 3 25 N 3 7 5 N ot 44 5m 2 6 N 4 10 N Wall 2m SPACE FOR

A body starts from the origin and moves along the X axis such that the velocity at any instant is given by 4t 2t where t is in second and velocity in m s What is acceleration of the particle when it is 2 m from the origin A 28 m s C 12 m s B 22 m s D 10 m s

A ball is thrown at an angle 53 up to the top of a cliff of height 5m from a point at a distance 5m from the base as shown in figure If the 5x m s then x speed of projection is given by will be 53 5 10 AGRI 53 ist a feed for at vi m sax 53 5x 3 5 5

26 Potential energy of a particle moving along x axis under the action of only conservative force is given as U 10 4 cos 4x Here U is in Joule and x in metres Total mechanical energy of the particle is 16 J Choose the correct option a At x 1 25 m particle is at equilibrium position b Maximum kinetic energy of the particle is 20 J c Both a and b are correct d Both a and b and wrong

A ball is projected at an angle of 60 to the horizontal If ball has a velocity of 50 m s at the highest point then ball was projected with velocity v in m s find the value of 40 7 600 for Gal af ofan 50 V v m s 40 G

25 In a projectile motion if we plot a graph between power of the force acting on the projectile and time then it would be like a c P P1 26 Potential an t t P b d t t norm of particle moving along x axis

2 A particle of mass 2 kg starts moving in a straight line with an initial velocity of 2 m s at a constant acceleration of 2 m s Then rate of change of kinetic energy a is four times the velocity at any moment b is two times the displacement at any moment c is four times the rate of change of velocity at any moment d is constant throughout

For a particle moving under the action of a variable force kinetic energy position graph is given then K B Tech A C D At A particle is decelerating At B particle is accelerating At C particle has maximum velocity At D particle has maximum acceleration

Q11 A man is slipping on a frictionless inclined plane and a bag falls down from the same height Then the velocity of both is related as CBSE AIPMT 2000 a VB Vm b VB Vm c VB Vm d VB and Vm can t be related

4 A motorboat is racing towards north at 25 km h and the water current in that region is 10 km h in the direction of 60 east of south The resultant velocity of the boat is a 11 km h 1 c 33 km h b 22 km h d 44 km h

A Q10 If the speed of a vehicle is increased by 1 m s its kinetic energy is doubled then original speed of the vehicle is a 2 1 m s b 2 2 1 m s c 2 2 1 m s d 2 2 1 m s

A ball which is thrown vertically up from the top of a tower reaches the ground in 20s Another vertically downwards from the same position with the same velocity takes 10s to reach the ground What was its initial velocity take g 10 ms 2 O O 20 ms 30 ms 50 ms 1 1 1 20 ms

A football player kicked the ball at a speed of 27 0 m s as shown in the figure Determine the range and eight achieved by the ball at a given angle Assume that the speeds are the same at a different angle Angle 20 35 45 55 70 Time of flight 3 2 s 6 2 s 5 2 B Hieght 4 4 m 18 6 m Range 71 m

00 Which one of the displacement time moving with zero relative velocity a c Theplacement the following represents graph of two objects A and B Displacement Time Time b d dug Displacement Time

c 18 N along OC d N along OF 9 Rain is falling vertically with a speed of 35 m s Winds starts blowing after sometime with a speed of 12 ms in east to west direction At what angle with the vertical should a boy waiting at a bus stop hold his umbrella to protect himself from rain 12 a sin b cos 35 c tan 12 35 d cot 35 12 35

1509 A cricket ball of mass 150 g is moving with a velocity of 12 m s and is hit by a bat so that the ball gets turned back with a velocity of 20 m s If the duration of contact between the ball and bat is 0 01 s find the impulse and the average force exerted on the ball by the bat lution

A particle of mass 0 1 kg is subjected to a force which varies with distance as shown If it starts its journey from rest at x 0 then its velocity at x 12 m is F N 10 NF X 4 0 m s 20 2 m s 20 3 m s 40 m s x 8 x 12 x m

1 Two towns A and B are connected by a regular bus service with a bus leaving in either direction every T minutes A man cycling with a speed of 20 km h in the direction A to B notices that a bus goes past him every 18 min in the direction of his motion and every 6 min in the opposite direction The period T of the bus service is a 4 5 min c 12 min b 9 min d 24 min

Refer the system shown in the figure Block is sliding down the wedge All surfaces are frictionless Find correct statement s A Acceleration of block is gsin 0 C Tension in the string is mgcos 0 String m B Acceleration block is gcos D Tension in the string is mgsin0 cos

The path of a projectile thrown vertically upwards is as shown Select incorrect statement B C f A D Question Type Single Correct Type 1 time taken from A to B time taken from C to D 2 time taken from A to C time taken from B to D 3 velocity at B velocity at C

In the following arrangement the system is initially at rest The 5 kg block is now released Assuming the pulleys and string to be massless and smooth the acceleration of blocks is g 10m s g 7 B a 0 m s A a 5 C ac 7 m s D 2a a 5 kg A 10 kg B 8 kg placed on a smooth inclined plane and 2 kg

c 115 ms d 125 ms 90 A bus is moving with a speed of 10 m son a straight road A scooterist wishes to overtake the bus in 100 s If the bus is at a distance of 1 km from the scooterist with what speed should the scooterist chase the bus a 40 m s s 19 ms b 25 ms d 20 m s

with respect to the first as shown in the figure The equation of the linear part is by jm 120 100 80 60 40 2 a x x 501 c x x 15t 4 6 Ms N 16 b x x 10t d x x 201 a 15 km h c 60 km h RELATIVE VELOCITY 83 A ball A is dropped from a building of height 45 m Simultaneously another identical ball B is thrown up with a speed 50 ms The relative speed of ball Bw rt ball A at any instant of time is Take g 10ms a 0 b 10 ms d 50 m s c 25 m s 84 A ball A is thrown vertically upwards with speed u At the same instant another ball B is released from rest at height At time t the speed of A relative to Bis a u b u 2gt c u 2gh d u gt 85 Two cars A and B are running at velocities of 60 km h and 45 km h What is the relative velocity car B if both are moving of car A with respect to eastward b 45 km h d 105 km h 86 In question number 85 what is the relative velocity of a car A with respect to car B if car A is moving eastward and car B is moving westward a 15 km h b 45 km h 1 c 60 km h d 105 km h 87 On a two lane road car A is travelling with a speed of 36 km h Two cars B and C approach car A in opposite directions with a speed of 54 km h each At a certain instant when the distance AB is equal t AC both being 1 km B decides to overtake A before C does The minimum required acceleration of car B to avoid an accident is a 1 ms 2 c 2 ms 2 b 1 5 ms2 d 3 ms 88 A bird is tossing flying to and fro between two cars moving towards each other on a straight road One car has speed of 27 km h while the other has the speed of 18 km h The bird starts moving from first 39 car towards the other and is moving with the speed of 36 km h when the two cars were separated by 36 km The total distance covered by the bird is a 28 8 km c 48 8 km b 38 8 km d 58 8 km 89 A police van moving on a highway with a speed of 30 km h fires a bullet at a thief s car speeding away in the same direction with a speed of 192 km h If the muzzle speed of the bullet is 150 m s with what speed does the bullet hit the thief s car a 95 ms c 115 ms 90 A bus is moving with a speed of 10 m s on a straight road A scooterist wishes to overtake the bus in 100 s If the bus is at a distance of 1 km from the scooterist with what speed should the scooterist chase the bus a 40 m s c 10 ms b 105 m s d 125 ms b 25 m s d 20 m s 91 Two towns A and B are connected by a regular bus service with a bus leaving in either direction every T minutes A man cycling with a speed of 20 km h in the direction A to B notices that a bus goes pasti him every 18 min in the direction of his motion and every 6 min in the opposite direction The period T of the bus service is a 4 5 min c 12 min a 35 s c 11 6 s b 9 min d 24 min 92 A 175 m long train is traveling along a straight track with a velocity 72 kmh A bird is flying parallel to the train in the opposite direction with a velocity 18 kmh The time taken by the bird to cross the train is b 27 s d 7 s 93 Two parallel rail tracks run north south On one track train A moves north with a speed of 54 km h and on the other track train B moves south with a speed of 90 km h The velocity of train A with respect to train Bis a 10 m s c 25 m s b 15 m s d 40 m s 94 In the question number 93 what is the velocity of a monkey running on the roof of the train A against its motion with a velocity of 18 km h with respect to the train A as observed by a man standing on the ground a 5 ms c 15 ms b 10 m sl d 20 m s 95 A train A which is 120 m long is running with velocity 20 m s while train B which is 130 m long is

a 10 ms c 25 m s b 15 m s d 40 m s 94 In the question number 93 what is the velocity of a monkey running on the roof of the train A against its motion with a velocity of 18 km h with respect to the train A as observed by a man standing on the ground a 5ms 1 c 15 ms b 10 ms d 20 m s

c 11 6 s d 7 s 93 Two parallel rail tracks run north south On one track train A moves north with a speed of 54 km hand on the other track train B moves south with a speed of 90 km h The velocity of train A with respect to train Bis a 10 ms c 25 ms b 15 m s d 40 m s

87 On a two lane road car A is travelling with a speed of 36 km h Two cars B and C approach car A in opposite directions with a speed of 54 km h each At a certain instant when the distance AB is equal to AC both being 1 km B decides to overtake A before C does The minimum required acceleration of car B to avoid an accident is a Ims c 2 ms b 1 5 ms2 d 3 ms

Vu 85 Two cars A and B are running at velocities of 60 km h and 45 km h What is the relative velocity of car A with respect to car B if both are moving eastward a 15 km h c 60 km h b 45 km h d 105 km h

Two junglemen are standing at the two opposite banks of a river of width T facing each other One of them starts beating a drum and sound reaches to the other one after time he 4 starts Then second one starts beating the drum and now first one hear the sound after time t Calculate the velocity of sound relative to air and the velocity of wind if it is blowing from first bank to the other bank at right angle to the river flow

A graph of x versus t shown in x figure Choose correct alternatives from below X A B D E This question has multiple correct options B At B the acceleration a 0 Correct Answer A The particle was released from rest at t 0 O Correct Answer C At C the velocity and acceleration vanishes D Average velocity for the motion A and D is positive Correct Answer E The speed at D exceeds that at E

An object is moving in positive direction till time t and then turns back with the same negative acceleration The velocity time graph which best describes the situation is a b c ol d ol f

9 A body A starts from rest with an acceleration a After 2 seconds another body B starts from rest with an acceleration a If they travel equal distances in the 5th second after the start of A then the ratio a ay is equal to a 5 9 b 5 7 c 9 5 d 9 7

Two plate AB and CD are rigidly attached 1 perpendicular to base of a massive box Box is released on smooth inclined plane having angle of inclination 37 With what minimum speed with respect to box a particle is projected so as to graze top point A and C of plate AB 2m CD 3m Given Separation between top of plate is 3m Take g 10m s A 37 Smooth

70 The velocity of a particle at an instant is 10 m s After 3 s its velocity will becomes 16 ms The velocity at 2 s before the given instant will be a 6 ms c 2 ms 1 A body covers a distance b 4 ms1 d I ms1 c