Kinematics Questions and Answers

A particle is thrown up vertically with a speed vi in air It takes time in upward journey and 12 1 in the downward journey and returns to the starting point with a speed V2 Then A V V B Vi V C v V D Data is insufficient A

You are engaged in an experiment to determine the speed of sound in air known to be roughly 0 3 km s You arrange for another person to fire a gun at a point some distance away from you and you propose to measure with a stop watch the time taken for the sound of the gun fire to reach you a At what distance will you arrange for the other person to be 10 m 100 m 1000 m or more than 1000 m away from you 1000m Give reason to your answer b Write a brief note on how you would do the timing

A person is sitting on a cart which is accelerating with 10 3m s2 At a certain instant the person throws a ball vertically upwards with 20 3m s from his own frame Minimum radius of curvature in m of the ball as observed by person will be

A bullet of mass m is fired with speed vo on soft plywood of thickness t The bullet emerges with only half of the initial kinetic energy What is the emergent speed of the bullet ions 1 11 22 1 2 Uo 4 4 Vo 205 208302120553011229 1631512581473067 1 2

A particle is projected from the top of heighth with a velocity 2ngh The range on the horizontal plane through the foot of the tower is maximum when angle of projection is given by A tan 20 2n 1 B cos 20 2n 1 C sec 20 2n 1 D cot 20 2n 1

Q15 75 A particle of mass m and carrying charge q moves in a gravity free region with a uniform electric field present At t 0 the particle has velocity v At 7 To the particle has velocity v in a direction perpendicular to its direction at t 0 The magnitude of the electric field E is mv gt

A block of mass M at rest on the floor is attached to a ball of mass M 2 via a light inextensible string of length L which passes over a light small frictionless pulley The pul ley is at a height of 0 6L from the floor The ball is raised to a height of L 6 and released see figure The speed of the block at the instant the string gets taut not slack will be 0 6L AAAAAAA

In the figure shown a river of width 4 km is flowing with the speed of 5 km h A swimmer whose swimming speed relative to the water is 4 km h starts swimming from a point A on a bank On the other bank B is a point which is directly opposite to A What is the minimum distance in km that the swimmer will have to walk on the other bank to reach the point B Answer A B B A Your Attempt 1 5 km h 2 Correct answer Rate this question

A flare in a rescue mission aids rescuers to easily locate stranded people in desolate places like mountains and islands A rescue team tries to calculate the height a flare reach at a certain time If a flare is launched vertically upward from the ground at 25 m sec find the height of the flare after 4 seconds use a 9 8m sec

A bullet of mass 50 g is fired from below into a bob of mass 450 g of a simple pendulum as shown in figure The bullet remains inside the bob and the bob rises through a height of 1 8 m The speed of the bullet is g 10 m s 21 1 O 50 g 1 6 m s 450 g h

With the x axis horizontal and the y axis vertically upward as positive the change in the horizontal component of velocity Avx and the change in the vertical component of velocity Avy of a projectile are related to the time since leaving the barrel At as Avx 0 Avy 0 Avx gat Avy 0 Avx 0 Avy gat Avx 0 Avy gat 4

In the figure all pulleys P P2 P3 are massless and all the block 1 2 3 are identical each having mass m The system consist of infinite number of pulleys and blocks Strings are light and inextensible and horizontal surfaces are smooth Pulley P is moved to left with a constant acceleration of 4m s Find the acceleration of block 1 in m s2 Assume the strings to remain horizontal 4m s P P P P

3 12 km h 113 Acceleration a versus 1 graph of a particle moving in a straight line is as shown in figure Velocity of the particle are equal at a Os 5s 10 s 1 0 s and 20 s 2 10 s and 15 s 3 0s and 15 s 4 0s and 10 s 15 s 20 S 600156

S A body starting from rest accelerates uniformly at the rate of 10 cm s and retards uniformly at the rate of 20 cm s Find the least time in which it can complete a journey of 5 km if the maximum velocity attained by the body is 72 km h Question Type Single Correct Type 1 400 sec 2 500 sec 3 300 sec

motion Why do we use a a v accelerati on velocity graph Why don t we use th e anchor v t graph MAIN Equations of Projectile Motion y Let s resolve the projectile motion into two 1D motions a uniform velocity motion along x axis and a uniformly accelerated motion along y axis u Bu H X v t Y

A body of mass 2 kg is projected with speed 20 m s at an angle 30 with the horizontal from a height of 50 m Then find change in its momentum when it is just going to strike the ground Take g 10 m s 1 86 3 kg m s 3 90 4 kg m s 2 70 4 kg m s 4 80 kg m s

Read More Which of the following graph represents variation of vertica component of velocity of projectile motion oblique with time b L

A particle is placed in a cart Initially location of the particle is taken as origin in ground frame At t 0 the cart starts moving along x axis with uniform velocity 2 m s and at the same instant the particle starts moving with 2xj relative to cart where x is x coordinate of the car Which of the following is the radius of curvature of the trajectory of the particle in ground frame when it s tangential acceleration is equal to normal acceleration in magnitude 2 A m 3 2 2 C m B D m 771

Which of the following graph represents variation of vertica component of velocity of projectile motion oblique with time n

The average kinetic energy of hydrogen molecules at 300 K is E At the same temperature the average kinetic energy of oxygen molecules will be Question Type Single Correct Type 1 E 16 2 E 4 3 E

A bullet is shot straight up it takes the bullet 2 4 seconds to reach its greatest height A What was its velocity at its maximum height B What was its initial velocity C What is the greatest height it reaches D What is its final position exactly 4 00 seconds after it is shot Assuming that upwards is positive Final velocity at its maximum height Initial velocity greatest height it reaches final position after 4 23 54m s 9 81m s 28 24meters 28 24m s 14m s OO 00 O O O O O O 15 68 meters Om s O O O O OOOO OO 12 poin 16 46 meters

An aircraft takes off from a horizontal runway with constant speed v climbing at a constant angle a to the horizontal A car is moving on the runway with constant speed u directly towards the front of the aircraft The car is distance a from the aircraft at the instant of take off Find the distance of closest approach of the car and aircraft O O av sin a v2 u 2uv cos a av sin a v u 2uv cos a av cos a v2 u 2uv cos a 1 2 1 2 1 2

A particle of mass m moves in the positive direction with speed v at the origin If a force F kx acts the particle the distance from the origin where the particle stops is 1 mv k 2 2mv k 3 mv k 4 mv 2k

3 A block of mass 5 kg rests on a horizontal floor When a constant horizontal force is applied on the block for a time interval 5 s the block slides on the floor a distance 5 m under the action of the force and after the removal of the force it further slides a distance 1 m before coming to a stop Acceleration due to gravity is 10 m s a Magnitude of the applied force is 12 N b The maximum speed acquired by the block is 2 m s c Coefficient of friction between the block and the floor is 0 2 d The block continues to move for 1 s after the removal of the force

A particle leaves the origin with initial velocity v 111 14 m s It undergoes a constant acceleration m s When does the particle cross the y axis A 2 sec B 4 sec C 5 sec D 7 sec At the instant when particle crosses y axis direction in which particle is moving is 2 2 21 1 15 given by a 5 A At angle 37 from x axis towards y axis B At angle 37 from x axis towards y axis C At angle 53 from x axis towards y axis D At angle 53 from x axis towards y axis How far is it from the origin at that time B 71 67 m C 125 m D 15 m

man is standing on a road and observes that rain is falling at angle 45 with the vertical The man starts running on the road with constant acceleration 0 5 m s After a certain time from the start of the motion it appears that rain is still falling at range 45 with the vertical with speed 2 2 m s Motion of the man is in the same vertical plane in which the rain is falling Then which of the following statement s are true It is not possible Speed of the rain relative to the ground is 2 m s Speed of the man when he finds rain to be falling at range 45 with the vertical is 4 m s The man has travelled a distance 16m on the road by the time he again find to be falling at angle 45

A particle is projected from a point O in the horizontal surface OA with speed u and angle of projection 8 It just grazes the plane BC which makes an angle a with the horizontal The time taken by the projectile to reach Pr the instant of projection is 2u sine g cosa O usine g cosa O usin e a 0 0050 P f B 0 C A

A body moving from the origin in the positive x direction starts with a velocity 40 m s and has a uniform acceleration of 2m s2 till it reaches its point of rest How much 7 time does the body take to cover three fourth of the distance to the point rest 11 11

A glass wind screen of adjustable inclination is mounted on a car The car moves horizontally with a speed of 6 m s At what angle a with the vertical should the wind screen be adjusted so that the rain drops falling vertically with 2 m s strike the wind screen perpendicularly tan 1 2 B tan 1 3 C tan 1 4 tan 1 5

A stone is projected from point P on the inclined plane with velocity vo 10 m s directed perpendicular to the plane The time taken by the stone to strike the horizontal ground S is Given PO 10 m B 1 5 sec 1 4 sec 2 sec 2 3 sec 530

If the kinetic energy of a body is four times equals the numerical value of its momentum then velocity of the body is OPTIONS MARK FOR REVIEW CLEAR SELECTION OA 4 m s OB 8 m s 2 m s

If a body is released from a certain height during its fall OPTIONS MARK FOR REVIEW CLEAR SELECTION O A OB Both potential and kinetic energy of the body decreases Both potential and kinetic energy of the body increases

An airplane flies northwards from town A to town B and then back again There is a steady wind blowing towards the north so that fo the first stage of the trip the airplane is flying in the same direction as the wind and for the return half of the journey the airplane flying directly into the wind The total trip time Tw as compared to the total trip time in the absence of any wind To obeys W A B C Tw To Tw To Tw 2TO

Mitaali a class 10 student wanted to study the speed of reactions of different acids with zinc metal For this she conducted the following experiments using zinc metal in excess Acid used 100 mL of 0 2 mol L HCI 100 mL of 0 2 mol L H SO III 100 mL of 0 2 mol L CH COOH She measured the volume of H gas produced at regular time intervals and summarised her results in a graphical form Experiment I Which of the following graphs best represents the results obtained in experiments I II and III A C Volume of H cm Volume of H cm II 1 11 III Time s Time s 111 B D Volume of Hycm Volume of Hy cm II III Time s II Time s III

Indhu and Lavi run a race around a circular track The total length of the circular track is 198 meters At the half way point Indhu trips and falls down Lavi who was at the three fourth mark at this time runs back to help Indhu What is the magnitude of Lavi s displacement

From his house Shyam drives his car 16 km north for 7 minutes He stops for 10minutes to pick Madhu from her class Then he drives 12 km east in 8 minutes What was the magnitude of his average velocity

17 The position time graph regarding the motion of a car is given below Position metre 50 30 20 X 10 O Y Time second a What is the scale taken in the X and Y axis b Find the distance covered by the car in 4 second c Find the time at which the displacement becomes 45 m 10

Q5 A particle of mass m and charge q is released from rest in a uniform electric field If there is no other force on the particle the dependence of its speed v on the distance x travelled by it is correctly given by graphs are schematic and not drawn to scale 8 Jan 2020 11 a b c d X X

The figure shows the velocity and acceleration of a particle at the initial moment t 0 of its motion The acceleration vector of the particle remain constant Vo 8m s O The instant of time after t 0 at which the speed of the particle is 8 m s again is O O O 2s 8s 16s 0 120 4s a 2 m s

The position of a particle which moves along a straight t 6t 15t 40 line is defined by the relation x where x is expressed in meters and t in seconds Which of the graph does not represent the motion of the par ticle 1 2 3 4 x m 40 1 15m s v m s velocity time curve 2 Jo position time curve 0 12m s 15m s a m s acceleration time curve 118 t s 2 1 5 t s 5 velocity time curve 5 t s Q

The velocity time graph for the rectilinear motion of a particle is represented by a parabola as shown in Figure The distance traveled by the particle in the time T is VouT A max 2 VT C max 3 Velocity max B V T max D 2V T max 3 time

When an object is projected at angle then maximum height attained is H and when this is projected at angle with same speed then maximum height attained is H Here R R2 are ranges in these conditions If time of flight in both cases are T and T2 respectively then T T CO T T R 1 29T T Sal Ox 0

A particle is projected at the angle of 60 above the horizontal with a speed of 10m s After sometime the direction of its velocity makes an angle of 30 above the horizontal The speed of the particle at this instant is A 5 m s B 5 3m s C 5m s D 10 3 m s

A ball is thrown horizontally from the top of a tower with a speed 60m s After 3 sec A Magnitude of the velocity of the ball is 60m s B Angle made by the ball with the horizontal tan 49 C horizontal displacement of the ball is 180m D vertical position of the ball is 29 4m

A particle projected from the ground with an initial velocity of 20m s at an angle of 30 with horizontal The magnitude of change in velocity in a time interval from t 0 to t 0 5s is g 10m s A 5m s B 2 5m s C 2m s D 4m s

A particle having a velocity v v at t 0 is decelerated at the rate a a v where a is a positive constant A The particle comes to rest at t 2 vo B The particle will come to rest at infinity C The distance travelled by the particle is 2v3 2 D The distance travelled by the particle is 3 3 2 0

3 2 4 A person standing on a truck moving with a uniform velocity 14 7 ms on a horizontal road throws a ball in such a way that it returns to him after 4s Find the speed and angle of projection as seen by a man on the road 1 19 6 ms vertical 2 24 5 ms vertical

9 A ball is dropped from a height of 19 6 m above the ground It rebounds from the ground and raises itself up to the same height Take the starting point as the origin and vertically downward as the positive X axis Draw approximate plots of x versus t v versus t and a versus t Neglect the small interval during which the ball was in contact with the ground

The velocity of a particle moving along x axis is given as v x 5x 4 in m s where x denotes the x coordinate of the particle in metres Find the magnitude of acceleration of the particle when the velocity of particle is zero A 0 m s B 2 m s C 3 m s D None of these

SECTION 2 NUMERICAL ANSWER BASED QUE The distance x covered by a particle in one dimensional motion varies with time t as x a 2bt c If t acceleration of the particle depends on x as x where n is an integer the value of n is JEE Main 2020 Onli