Kinematics Questions and Answers

ith a velocity with a speed ne motion of ange is given 75 to the nge when Pre Medical Physics 120 Three projectiles A B and C are thrown from the same point in the same plane Their trajectories are shown in the figure Which of the following statement is true ABC 1 The time of flight is the same for all the three 2 The launch speed is largest for particle C 3 The horizontal velocity component is largest for particle C 4 All of the above

26 A body travels for 15 sec starting from rest with constant acceleration If it travels distances S S and s in the first five seconds second five seconds and next five seconds respectively the relation between S S and s is a s S S c S S b 58 35 S s d s a

A man standing on a cliff claps his hand and hears its echo after one second If the sound in reflected from another mountain then the distance between the man reflection points is V sound 340 m sec Question Type Single Correct Type 1 680 m 2 340 m 3 170 m 25 m

23 A car moving with a speed of 40 km h can be stopped by applying brakes after atleast 2 m If the same car is moving with a speed of 80 km h what is the minimum stopping distance a 8 m c 4 m b 2 m d 6 m

17 A particle experiences a constant acceleration for 20 sec after starting from rest If it travels a distances in the first 10 sec and a distance s in the next 10 sec then b S S 3 d s S 4 a s S c S S 2

A sphere of mass m radius R placed between two vertical walls having separation d which is slightly greater than 2R i Calculate force exerted by walls on the sphere ii Calculate force exerted by ground surface on the sphere wall R wall Surface

One night a boy of height h is walking at a constant speed vo along the edge of a straight horizontal sidewalk moves past a lamppost The lamppost is at a distance 1 from the edge of the sidewalk and lamp installed on it is at a height H above the ground As the boy walks osition and size of his shadow on the ground continuously change Jove a Find velocity vector of shadow of his head H h b Find time rate of change in length of his shadow as a function of position x y of the boy As h yoo H h 4 42 H x

Non uniform motion 15 A train starts from rest from a station with acceleration 0 2 m s on a straight track and then Comes to rest after attaining maximum speed on another station due to retardation 0 4 m s If Total time spent is half an hour then distance between two stations is Neglect length of train 1 216 km E 2 512 km AP 3 728 km 4 1296 km D light of Dreams

Flight of Dreams 13 A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm How much further it will penetrate before coming to rest assuming that it faces constant resistance to motion a 1 5 cm c 3 0 cm b 1 0 cm d 2 0 cm

10 A man walks on a straight road from his home to a market 2 5 km away with a speed of 5 km h Finding the market closed he instantly turns and walks back home with a speed of 7 5 km h The average speed of the man over the interval of time 0 to 40 min is equal to JE km h d Flight of Dreams a 5 km h c 30 b 25 km h 45 km h

16 A particle start moving from rest state along a straight line under the action of a constant force and travel distance x in first 5 seconds The distance travelled by it in next five seconds will be 1 x 2 2 x 3 3 x

2 A car moves with speed 60 km h for 1 hour in east direction and with same speed for 30 min in South direction The displacement of car from initial position is 1 60 km 2 30 3 km 3 30 5 km 4 60 2 km

12 A particle moves for 20 seconds with velocity 3 m s and then velocity 4 m s for another 20 seconds and finally moves with velocity 5 m s for next 20 seconds What is the average velocity of the particle a 3 m s b 4 m s c 5 m s d Zero

In the arrangement shown in the figure a wedge of mass mz 3 45 kg is placed on a smooth horizontal surface Small and light pulley is connected on its top edge as shown A light flexible thread passes over the pulley Two blocks having mass m 1 3 kg and m 1 5 kg are connected at the ends of the thread m m m 37 m is on smooth horizontal surface and m rests on inclined smooth surface of the wedge The base length of wedge is 2 m and inclination is 37 m is initially near the top edge of the wedge If the whole system is released from rest calculate a Velocity of wedge when m reaches its bottom 10 ms 2

A motor boat 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 nearly NCERT Pg 72 1 22 km h 2 12 km h 3 35 km h 4 26 km h

8 A particle starts from point A moves along a straight line path with an aceleration given by a p qx where p q are constants and x is distance from point A The particle stops at point B The maximum velocity of the paticle is P P

In one nens motion instantaneous speed V satisfies 0 V Vo 1 The displacement in time T must always take nonnegative values 2 The displacement x in time T satisfies V T x V T 3 The acceleration is always an nonnegativ number 4 The motion has no turning points

surface of earth with initial velocity u u u as shown in figure The proportional to H maximum height and T time of flight T y 1 u Ux UxxUy u X

starts from rest from the point A and comes to rest at point B on the same straight line It moves over the first part of the total distance with uniform acceleration and the remaining with uniform retardation The ratio of maximum speed to average speed is 1 2 2 1 1 1 4 1

Two balls having linear momenta p pi and p pi undergo a collision in free space There is no external force acting on the balls Let p and p2 be their final momenta The following option s is are NOT ALLOWED for any non zero value of p a a b b c and ca 2008 A p a i b j c k B p ck P a i b j C p a i b j c k P a i b j c k P C k D p a i b j P a i b j

A man standing on a horizontal road holds an umbrell at 30 with the vertical to keep himself dry He then runs at a speed of 10 m s and find the rain drops to b hitting vertically The velocity of rain w r t man is 20 m s 30 m s 10 m s 10 3 m s

A small squirrel is put into a circular wheel eage of radius R which has a frictionless central pivot A horizontal platform of length is fixed to the wheel below the pivot as shown Initially squirrel is at rest at one end of the 6R 5 platform When the platform is released squirrel starts running but platform and wheel remain stationary Choose the correct options 6R 5 maximum speed of squirrel is Maximum speed of squirrel is Rg 9Rg 20 4g Maximum Acceleration of squirrel is

An object starts from rest from the point A and comes to rest at point B on the same straight line It moves over th first part of the total distance with uniform acceleration and the remaining with uniform retardation The ratio of maximum speed to average speed is 1 2 2 1 1 1

Under the action of a force a 2 kg body moves such that its position x as a function of time is given by x t 3 where x is in metre and t in seconds The work done by the force in the first two seconds is 1 1 6 J 3 160 I 2 16 J 4 64 3 J

2 7 A train starting from rest accelerates uniformly and attains a velocity of 48 kmh in 2 minutes It travels at this speed for 5 minutes Finally it moves with uniform retardation and is stopped after 3 minutes Find the total distance travelled by train

On a cricket field a rabbit is at the origin of coordinate system and a dog at the position 46 m 28 m The rabbit runs on the ground with a constant velocity 7 5 10 m s The dog can run with a speed 5 m s If the dog starts to run immediately the rabbit starts what is the minimum time in which the dog could catch the rabbit

Ex 8 If particles slide down chords of a vertical circle to its lowest point and are then allowed to move freely prove that the locus of the foci of their subsequent paths is a cardioide af

Two asteroids each of mass of mass M and radius R are moving in free space At an instant when their velocity vectors are and respect ively position vector of the second with respect to the first is 2 Determine the condition under which they will collide

1 2 3 A car has a velocity of 10 ms It accelerates at 0 2 ms for half minute Find the distance travelled during this time and the final velocity of the car 390 m 16 ms 1

agraph carefully and answer the following questions A tank has a hole of area 2 cm at its bottom and in this hole a conical cork is placed and water is filled up The water level is made to fall slowly by means of another orifice in the tank When the water level comes to a height of H cm the conical cork just comes out from the hole Given volume of water displaced by the cork 80 cm mass of the cork 40 gm Area of hole 2 cm density of water 1 gm cm Area of circular cross section of conical cork 8 cm Height of cork submerged in water Po 10 N m 120 22 cm Take g 10 m s n and 7 7 76 Calculate the value of H A 15 cm C 22 cm B 20 cm D 17 cm

A E 37 A thick shell with radius 2R has uniform density p C m It has a spherical cavity of radius R as shown in the figure A charge particle of mass m and charge Q is projected along the line AB at an angle 8 in the cavity as shown Select the correct statement Assume particle doesn t comes out of cavity u sin 20 QpR A 3m from point A u B A Particle crosses line AB at a distance of B Average velocity of particle during the time it crosses line AB is greater than u cos 0 C Final speed when it crosses line AB is equal to initial speed D It will move in a parabolic path in the cavity

A hot air balloon consists of a basket one passenger and some cargo Let the total mass be M even though there is an upward lift force on the balloon the balloon is initially accelerating downwards at a rate of g 3 The passenger notices that he is heading straight for a waterfall and decides he needs to go up What fraction of the total wight must he drop overboard so that the balloon accelerates upward at a rate of g 2 Assume that the upward lift force remains the same

A 3 0kg mass is moving in a plane with its x and y coordinates given x 5t 1 and y 3t 2 where and y are in meters and t is in seconds Find the magnitude of the net force acting on this mass at T 2 sec

17 A minivan travels straight north in the right lane of a C divided highway at 28 0 m s A camper passes the mini van and then changes from the left lane into the right lane As it does so the camper s path on the road is a straight displacement at 8 50 east of north To avoid cutting off the minivan the north south distance between the camper s back bumper and the minivan s front bumper should not decrease a Can the camper be driven to satisfy this requirement b Explain your answer

Q 2 A particle is projected with a velocity 61 8j 3m away from a vertical wall After striking the wall it land way from the wall collision is perfectly elastic Answer A 3m 3 3m C 5 5m Rate this question

A Spherical Steel ball of density P of radius r falls under gravity through a vertical column of a fluid density P of coefficient of viscosity n Will the ball attain constant velocity if yes then under what condition can this condition be used to find the value of m2 Justify giving necessary expression pleas

Speedometer shows speed and odometer shows distance travelled both relative to the surface on which the vehicle moves Two conveyor belts each of length L 500 m are arranged along a line one after the other with a negligible gap The belts are running in the same but unknown direction with constant speeds u 20 km h and u 30 km h A toy car installed with both the instruments runs on the belts one after the other spending t 72 s on them The speedometer shows constant readings on each of the belts and the odometer shows a total reading of s L 500 m Find the speedometer readings on each of the belts

A car travels a certain distance between 0 seconds and 2 seconds If we defined its velocity as v t 6t 5 then distance in meters is here v 1 1 m 2 2 m 3 3 m 4 4 m ds dt

A small disc of mass m is attached to one end of a light inextensible cord which passes through a frictionless hole in a frictionless horizontal tabletop At the other end of the cord is attached a weight of mass M Initially the disc is moving on a circle of radius R with an angular velocity If the hanging weight is pulled slightly downwards and then released it will undergo small amplitude oscillations Find the angular frequency of these oscillations

In the diagram the imput is across the terminals A and C and the output is across the terminals B and D then the output is B A D 1 zero 2 Same as input 3 Full wave rectifier

Two conductors of equal volumes having non uniform cross section are joined as shown in figure The number density of free electrons is more in conductor 2 As current passes through the system Which of the following option is correct 1 dC Drift speed of electrons at a Drift speed of electrons at b Drift speed of electrons at c Drift speed of electrons at d X Drift speed of electrons at c Drift speed of electrons at a Drift speed of electrons at b Drift of speed electrons at a

A block of mass m is placed on a smooth incline plane of inclination with the horizontal T inclined plane is accelerated horizontally so th the block does not slide down What is the vertic force exerted by the inclined plane on the block 1 mg sin 0 2 mg cos 0 3 mg 4 None of these

0 Illustration 3 53 A particle of mass m 1 kg collides with the end with velocity v 6 ms of a spinning rod of mass 2m and length 1 m at the end of the rod If the coefficient of restitution of collision e 2 3 find the a velocity of the particle b angular velocity of the rod just after the impact 1 1 m m 16 6 m s b 6 rad s Fig 3 162

A particle is projected with a velocity u making at angle with the horizontal at any instant its velocit v is at right angle to its initial velocity u then v is 1 u cose 2 u tan 3 cotA 11 sect

Sn60 A man is holding an umbrella at angle 30 with vertical with lower end towards himself which is appropriate angle to protect him from rain for his horizontal velocity 10 m s Then which of the following will be true VSING Yo teraso Wrt man A rain is falling at angle 30 with vertical towards the man B rain may be falling at angle 30 with vertical away from the man vcoso V cose VSine 10 3y cose van vane 10 t

A ball is thrown horizontally from the edge of a building at height 10 m above the ground The ball reached the ground at distance d 25 m from the base of the building as in figure the speed of the ball when it hits the ground is d 25 m ball 14 4 O

0 A ball dropped on a large inclined plane bounces repeatedly Every bounce is perfectly elastic i e there is no loss of speed and lines of motion make equal angles with the incline plane before and after the bounce Find ratio of distance R 2 between the first and the second bounce to distance R 3 between the second and the third bounce

3 The mass defect in a particular nuclear reaction is 0 3 g The amount of energy liberated in kilowatt hours is velocity of light 3x108 ms 1 a 1 5x106 c 3x106 b 2 5 106 d 7 5x10 or the masses of X nucleus neutron

A drunkard is walking along a straight road He takes 5 steps forward and 3 steps backward and so on Each step is 1 m long and takes 1 s There is a pit on the road 11 m away from the starting point The drunkard will fall into the pit after b 29 s a 21 s c 31 s d 37 s

27 The relation 3 3x 6 describes the displacement of a particle in one direction where is in in sec The displacement when velocity is zero is b 12 metres d Zero Flight of Dreams metres and a 24 metres c 5 metres