Kinematics Questions and Answers

KN013 137 A projectile is projected with initial veloci 61 8 m s If g 10 ms then horizontal rang is 1 4 8 metre 3 19 2 metre 2 9 6 metre 4 14 0 metre KN013

134 A ball is thrown at different angles with the same speed u and from the same point it has the same range in both the cases If y and y be the heights attained in the two cases then y y 2u g 3 g 2 4

The 1 1b collar is released from rest at A and travels along the frictionless guide Figure 1 Figure 1 of 1 1 5 ft 1 ft k 4 lb ft Determine the speed of the collar when it strikes the stop B The spring has an unstretche length of 0 5 ft Express your answer to three significant figures and include the appropriate units VB Submit 0 Value Units My Answers Give Up www Provide Feedback Con

2 A person moves towards East for 3 m then towards North for 4 m and then moves vertically up by 5 m What is his distance now from the starting point a 5 2 m c 10 m b 5 m d 20 m

person moves 30 m North and then 20 m towards East and finally 30 2 m in South West direction The displacement of the person from the origin will be a 10 m along North c 10 m along West b 10 m long South d Zero

4 In the direction of acceleration The shape of the trajectory of an obje determined by INCERT P 1 Acceleration only 2 Velocity of projection only 3 Initial position and initial velocity onl 4 hitial positional velocity acceleration

93 A parallel bearn of light from a monochromatic source is passed through a nicol prism When the nicol is rotated about the incident ray as the axis the intensity of light emerging out of the prism 1 remains constant 2 will be zero 3 varies between maximum and zero 4 varies between certain maximum and non zero minimum

EXERCISE 31 A ball is dropped from heighth on a horizontal floor If it loses 60 of its energy on hitting the floor the upto which it will rise after first rebounce is 2 2h

then wor A man of mass 50 kg is standing in an elevator If elevator is moving up with an acceleration done by normal reaction of floor of elevator on man when elevator moves by a distance 12 m i g 10 m s 1 2000 J 2 4000 J m 00001

Paragraph for question nos 17 to 19 Ram has just learnt driving and he is driving on a wet straight road 0 1 0 05 with a speed of 108 km hr He sees his friend Shyam ahead travelling at a constant speed of 36km hr in the same direction His horn fails he is at a distance of 102 m from Shyam He applies brakes just hard enough to prevent slipping yet providing for maximum deceleration What is his speed at the time of hitting Shyam A 24 m s B 21 m s C 18 m s 1 D 26 m s

2 3 A cannon ball is thrown with an initial velocity of 40 m s at an angle of 53 above the horizontal from ground After some time the ball is seen to travel at an angle of 37 below horizontal Find the time elapsed in second till then 1 3 3 5 2 7 4 8

5 A stone falls freely under gravity It covers distances h h and h3 in the first 5 seconds the next 5 seconds and the next 5 seconds respectively The relation between h h and he is NEET 2013 h h3 124 3 5 2 3h and h 3h 3 h h h 4 h 2h 3h is from th scooteri 1 40 m 3 10 r 12 A particl of a con 10 secc 20 seco 1 S 3 S

The diagram below not drawn to scale shows the journey of a ship which started at port P sailed 15 km due south to port Q and then a further 20 km due west to port R P zat

A car of mass m0 is moving with a velocity v0 along a straight track If in a time interval to magnitude of its velocity is increased by 200 and its direction of motion is reversed then magnitude of change in its momentum in this time interval is equal to n mv0 find n Take n positive

Which of the following statement is true Options Magnitude of average velocity and average speed are always equal A body with non zero acceleration can have constant velocity A body with zero velocity at an instant can have non zero acceleration Magnitude of velocity may change for an object in uniform motion

LW W W 5 Two pendulum bobs A and B of mass respectively are simultaneously released from a height H above the lowest point making an elastic collision at the lowest point If after the first collision A and B rise to heights h and h respectively then h 2h is 1 3H 2 H H

An object of mass m is sliding down a hill of arbitrary shape and after travelling a certain horizontal path stops because of friction The work done that a force must perform to return the object to its initial position along the same path would be 1 O 12mgh h 2 mgh 4 None of these

constant velocities along X axis at time t 0 seperation between both is 20 m Take usual sign convention Choose correct graph of position of A with respect to B IAB VS time 6m s 4m s A B C D A 0 0 A B A B A B A B 20 m 10 10 10 B X

A ball is thrown with 50 m s at 30 with the horizontal from a building of height 500 m The time in sec at which velocity vector of the ball becomes perpendicular to the initial velocity is g 10 m s

Velocity v versus displacement x plot of a body moving along a straight line is as shown in graph The corresponding plot of acceleration a as a function of displacement x is VA 0 X 0 X X3 X

0 8x here x and y are horizontal and vertical positions in meters If the body is thrown vertically upwards with with same speed of projection the distance travelled in m by the body during its flight is Neglect any frictional force on body and gravity is uniform over the planet

Two forces of equal magnitude act at a point making an angle with each other If the direction of one of the forces is reversed the direction of the resultant will turn through a 30 60 b 45 d 90

21 When a bullet is fired at a target its velocity decreases by half after penetrating 30 cm into it The additional thickness it will travel before coming to rest is 1 50 cm 2 40 cm 3 30 cm 4 10 cm

If we throw a ball vertically above then i t crosses all the points 2 times one goi ng on up and one on down so if i take a ny point at random is the magnitude o f velocity is same both the times Als o the initial velocity when the ball is thr own is same as the final velocity befor

Examine the graphs below Runner 1 Graph A Distance yards 40 35 30 25 20 15 10 5 0 Graph C Distance yards 40 35 30 25 20 15 10 5 0 1 1 Runner 2 2 Time seconds 3 2 Time seconds 3 Runner 1 Distance Time Graphs Practice Problems 4 4 Distance yards Distance yards Graph B 40 35 30 25 20 15 10 5 0 40 35 30 25 20 15 10 5 Which graph had the fastest runner How do you know 5 0 1 Graph D 1 2 Runner 2 3 Time seconds 1 Which of the graphs show that one of the runners started 10 yards further ahead of the other 2 Explain your answer 3 In graph D which of the runners is faster 4 Calculate the speed of Runner 1 and Runner 2 for Graph D 2 Time seconds 3 4 4

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 s 2015 The figures are schematic and not drawn to scale 1 y2 y m 2 3 240 240 12 V y m 8 t s 12 t s 4 240 240 y2 y m 8 y2 y m t 8 12 t s 12 t s

modeled as a 71 cm long uniform cylinder with a mass of 3 4 kg Y Part A In raising both his arms from hanging down to straight up by how much does he raise his center c gravity Express your answer with the appropriate units A 20 M

5 A ball is hit by a batsman at an angle of 37 as shown in figure The man standing at P should run at what minimum velocity so that he catches the ball before it strikes the ground man started runing at the time of hitting the ball Assume that height of man is negligible in comparison to maximum height of projectile g 10m s u 20 m s A A 3 m s C 9 m s 37 man PH 7 2 m B 13 m s D 12 m s B

32 A biker stands on the edge of a cliff 490 m above the ground and throws a stone horizontally with an initial speed of 15 m s Neglecting air resistance find the time taken by the stone to reach the ground and the speed with which it hits the ground Consider g 9 8 m s NCERT Sol Given h 490 m ux 15 m s 9 8 m s ax 0 y 0 A ori y 490 m A Time taken by the stone is 2 490 1 t Ground V 2h V g 9 8 vy Vx ux axt 15 0 x 10 15 m s Vyuy a t 0 9 8 x 10 98 m s x 15 98 99 14 m s v 10 s P 2 1 1

Theifs car is moving with a speed of 10 m s A police van chasing this car with a speed of 5 m s fires a bullet at the theifs car with muzzle velocity 72 km h Find the speed with which the bullet will hit the car A 10 m s C 15 m s B 20 m s D 25 m s

You have different strings with weights tied at various point all hanging from the ceiling and reaching down to the floor Initially all weights are at rest The string is released at the top allowing the weights to fall Which setup can create a sound at regular interval as the weights hit the floor A B C D

the displacement x in meter of a particle of mass W in kg moving in one dimension under the action of a force is related to time t in sec by t x 3 The displacement of the particle when its velocity is zero will be A 4 m B 0 m zero C 6 m D 2 m

A particle moves along a straight the OX At a time t in second displacement of the particle from O is given by x 40 12t t How long would the particle travel before coming to rest A 24 m C 36 m B 40 m D 16 m

balloon has a mass of 5 g in air The air escapes from the balloon at a uniform rate with a velocity of 1 5 cms If the balloon shrinks completely in 2 5 s find the average force acting on the balloon

A ball is projected horizontally from some height After 3 s from projection its velocity becomes 2 times of the velocity of projection Its velocity of projection is A 10 m s B 10 3m s C 30 m s D 40 3 m s

From the following velocity time graph of a body the distance travelled by the body and its displacement during 5 seconds in metres will be velocity m sec 40 30 20 10 10 20 30 40 A 75 75 C 110 110 No 5 t in sec B 110 70 D 110 40

E OBLIQUE PROJECTILE 60 The initial velocity of the projectile is equal to the velocity acquired by a freely falling body on reaching ground when it is dropped from height h Then maximum horizontal range of that projectile is mum 10 3 h 2 Tote 4 1 h 2 2h 61 A projectile is fired at an angle of 45 and reaches the highest point in its path in 2 2 s If air resistance is neglected maximum height reached by it is 2 2g 1 g 3 3g 4 4g 52 The speed of a projectile at its maximum height is 6m s If it stays in the air for a total time of 8 seconds its ime o horizontal range is 118m 4 2h OL

The bob of mass m of a pendulum of length I is given a horizontal velocity 6gl as shown in the figure there is no air resistance BO Tension at highest point is mg Tension at lowest point is mg Velocity at highest point is 2gl String will not stack anywhere 1 6gl

A particle is seen from reference frame s s Reference frame s is moving with acceleration a with respect to reference frame s Assuming F F are pseudo force on particle while we see from frames s s respectively Which of following is not possible 1 F 0 F 0 1 2 3 F 0 F 0 1 2 F 0 F 0 2 4 F 0 F 0 2

Example 1 8 An electron falls through a distance of 1 5 cm in a uniform electric field of magnitude 2 0 x 104 N C Fig 1 13 a The direction of the field is reversed keeping its magnitude unchanged and a proton falls through the same distance Fig 1 13 b Compute the time of fall in each case Contrast the situation with that of free fall under gravity e I e

A uniform ladder 14m long and weight 400N is placed against a vertical wall at an angle of 60 with the ground How far along the ladder can 1600N man climb before ladder is slipping Take an angle of friction at all the surface is 25 60 B

2 M m Block B is moving towards right with constant velocity vo Velocity of block A with respect to block B is Assume all pulleys and strings are ideal 1 v 2 left 3 3 2v right If masses are released from the position shown in fig then speed of mass m 2 v 2 right 4 3 2v left A 1 G B Vo

28 A force F i 4 acts on the block shown The force of friction acting on the block is 3 2 47 Lxx x 1 kg TTT 0 3 777 2 18 4 37

40 In n and v be the number of elect tro d velocity in a semiconductor temperature is increased 1 n increases and v decreases 2 n decreases and v increases e 3 Both n and v increases Va e d 4 Both n and v decreases e

Three blocks A B and C of mass 4 kg 1 kg and 3 kg respectively are arranged as shown with two ideal pulleys P and Q and massless strings The block A rests on a fixed smooth horizontal surface The pulley P is fixed The system is released from rest The accelerati the block B is A B

cost A block of mass m takes time f to slide down on a smooth inclined plane of angle of inclination 0 and height h If same block slids down on a rough inclined plane of same angle of inclination and same height and takes time n times of initial value then coefficient friction between block and inclined plane is 1 1 tan o 3 1 n tan 0 2 4 tano tane

A cat on seeing a rat at a distant of d 5 m starts with velocity u 5 ms and moves with acceleration a 2 5 ms in order to catch it while the rat with acceleration 3 starts from rest For what value of will be the cat overtake the rat in ms 2 a 5 b 10 c 12 d 15

4 zero 6 Two blocks are connected by a cord passing over a small frictionless pulley and resting on frictionless planes as shown in the figure The acceleration of the blocks is 7 1 0 33 m s 3 1 m s2 Two masses are suspended vertically 2 0 66 m s 4 1 33 m s 100kg 37 50 kg 53

A simple pendulum A and a homogeneous rod B hinged at its end are released from horizon position as shown in figure PHYSIC 27 2 1 A B L A The time period of swing of simple pendulum is greater than that of rod if L B The time period of swing of simple pendulm is equal to that of rod if L C The time period of swing of simple pendulum is greater than that of rod if L 20 D The time period of swing of simple pendum is equal to that of rod if L 20 3

Column A b a b axb c a b d 3 b Column B p is commutative q does not change sign under reflection r is perpendicular to axb s Always less than or equal b a s b q c p d r a s b q c r d p e a s b r c q d p C