Kinematics Questions and Answers

Q13 An aeroplane moving horizontally with a speed of 180 km h drops a food packet while flying at a height of 490 m The horizontal range of the packet is a 180m b 980 m c 500m d 670m STOM

A block of mass m 2 90 kg initially moving to the right with a speed of 8 00 m s on a frictionless horizontal track collides with a spring attached to a second block of mass m 5 10 kg initially at rest Find the velocities of the two blocks after the collision show how you derive the formula

ustration 32 A particle thrown over a triangle from one end of a horizontal base falls on the other end of the base after grazing the vertex If a and are the base angles of triangle and angle of projection is 0 then prove that tan 0 tan a tan 01 03 KINEMATICS

ration 24 A block slides down a smooth inclined plane when released from the top while another falls freely from same point Which one of them will strike the ground a earlier b with greater speed on

all body ess surface from rest on an inclined plane If Sn is the distance travelled in time t n 1 to t n then the ratio of S and Sn 1 will be nti to 1 2 3 4 2n 1 2n 2n 1 2n 1 2n 1 2n 1 2n 2n 1 on a 7 60 100 Key

A boy stands 78 4 m away from a building and throws a ball which just enters a window at maximum height 39 2m above the ground Calculate the velocity of projection of the ball A 78 4m 39 2m B

A particle is thrown vertically upwards from the surface of the earth Let Tp be the time taken by the particle to travel from a point P above the earth to its highest point and back to the point P Similarly let To be the time taken by the particle to travel from another point Q above the earth to its highest point and back t the same point Q If the distance between the points P and Q is H find the expression for acceleration du to gravity in terms of Tp To and H AIPMT Mains 200

A car of mass 1000 kg accelerates uniformly from rest to a velocity of 54 km h in 5s The average power of the engine during this speed is neglect friction Question Type Single Correct Type 1 2000 W 2 45000 W 3 2250 W 4 22500 W

2 A swimmer heads directly across a river swimming at 1 6 m s relative to water She arrives at a point 40m downstrem from the point directly across the river which is 80 m wide Find time taken to cross the river 1 30 s 3 50 s 2 40 s 4 60 s

The velocity displacement graph describing the motion of a bicycle is shown in the figure v ms 1 1 200 400 x m The acceleration displacement graph of the bicycle s motion is best described by tions a ms 2 2 3 50 4 10 0 18 2 0 a ms 1 1 18 2 0 a ms 2 1 18 2 0 a ms 2 18 2 200 400 x m 0 200 400 x m 200 400 x m 200 400 x m

Q 1 A Frame is shown in the given figure Floor reaction at A and vertical pin reaction at D are respectively Note the reaction force at A and E have only single vertical force A 757 N and 1142 N B 612 N and 1013 N C 757 N and 1241 N D 612 N and 1142 N E No one of above write your answer 4 cm 60 12 cm 180 45 9 cm 5 cm

A truck is moving with a constant velocity of 54 km h In which direction angle with the direction of motion of track should a stone be projected up with a velocity of 20 m s from the floor of the truck so as to appear at right angles to the truck for a person standing on the earth A B COS Correct Answer 1 COS 1 1 COS 1 1 3

If straight lines ax by p 0 and xcosa ysina p 0 includ an angle 4 between them and meet the straight line xsina ycosx o in the same point then the value of a b is equal to A 1 C 3 B 2 D 4

Two boys are standing near the ends of a 100 m long conveyor belt that is running with a constant velocity 1 0 m s The boys step on the conveyer belt on its opposite ends and start walking towards each other After meeting they immediately return towards the ends of the belt and then continue the process repeatedly The boys walk with a constant speed of 3 m s relative to the conveyer belt What distance relative to the ground do the boys walk in the first 300 s

students can refer m 2 1 A packet of 150 kg is released from an airplane travelling 2 due east at an altitude of 7200 m with a ground speed of 100 m s fi The wind applies a constant force on the packet of 300 N directed horizontally in the opposite direction to the plane s flight path Where and when does the packet hit the ground with respect to the release location and time Ans 38 s 2 36 km

2 9 When an archer pulls on the bow string with a force of 500 N the bow string makes angles of 53 with the arrow What is the tension in the string

A block slides down an inclined plane of inclination 0 with constant velocity It is then projected up the inclined plane with an initial speed u How far up the incline will it move before coming to rest u 4g sine u 2 u gsine u

The body is rotated in the vertical plane by means of a thread of length with minimum possible spee At the highest point B the thread breaks and the body moves under gravity and strikes at C Then Option A B C D B A The horizontal range AC is 20 The horizontal range AC is 2l Tangential acceleration of the body at point C is 58 Tangential acceleration of the body at point C will be g Rate this q

a particle has a velocity v at origin at t 0 and it is acted upon by force which supplies it an instantaneous power given by P Kv2 where k is a positive constant and v is instantaneous velocity Find the charge in momentum when it reaches a position x xo kxo 3 kx 2 2 2kx 4 4kx

Snow is falling vertically at a constant speed of 7 0 m s At what angle from the vertical direction do the snowflakes appear to be falling as viewed by the driver of a car travelling on a straight level road with a speed of 16 m s a 36 b 56 c 66 d 106

Ex A road connecting two towns contains a bridge over a river crossing the road somewhere between the towns Two cars travel from one town to the other at constant speed everywhere on the road except on the bridge where they travel at constant speed In the graph is shown variation in separation between the cars with time 44 100 a What is speed v of the cars on the road b What is speed v of the cars on the bridge c What is length L of

51 A disc of radius 1 m is rotating about central axis with angular velocity 2 rad s If a point P lying on its circumference as shown is moving with velocity 47 m s then speed of centre of disc is n m s The value of nis P

A point source of light is placed 4 m below the surface of water of refractive index 5 3 The minimum diameter of a disc which should be placed over the source on the surface of water to cut off all light coming out of water is a 1 m c 3 m b 4 m d 6 m

The height h in metres of a weather balloon above the ground after t seconds can be modelled by the function h t 2 32 149t 410 for osrs 10 When is the balloon exactly 980 m above the ground

Water jet comes out from a point O on the ground at a speed v at angle 45 with horizonta as shown The speed v of jet so that it can we the man upto his head will be g 10 m s H 45 1 10 m s 10 To 3 m s 4 m man 2 4 2 10 2 m s 4 100 m s 4 15

A body is projected upward with speed v not along this line of greatest of inclin ed plane of angle of inclination theta wi th the vertical direction perpendicular t o the inclined plane find the time after which the body for replacement of phys ician in this question how did you deriv e the value of cos alpha

A fixed rifle is aimed at a point on a vertical wall 1440 m horizontally away and 1080 m high above the point of the rifle end A bullet is fired at 150 m s towards the target 10 sec after firing the gravitational field vanishes find where the bullet will hit the vertical wall from ground If your answer is x meter Fill value of X 100 g 10 m s

Imagine a man moving from North Pole to the equator and from the equator to the South Pole moving along the same longitude Find the magnitude of the displacement in the first part second part and total displacement is sqrt 2 R sqrt 2 R 2R O R sqrt 2 R sqrt 2 R OR 2R Zero O2R 2R Zero

A 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 to him that rain is still falling at angle 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 is are true Question Type Multiple Correct Type 1 It is not possible 2 Speed of the rain relative to the ground is 2 m s Speed of the man when he finds rain to be 3 falling at angle 45 with the vertical is 4 m s The man has travelled a distance 16 m on 4 the road by the time he again finds rain to

The initial velocity v required to project a body vertically upward from the surface of the earth to reach a mathongo hongo mathongo mathongo height of 10R where R is the radius of the earth may be described in terms of escape velocity ve such tha mathon mathongo matha Vi xve The value of a will be mathongo mathongo mathongo matha

PHYSICS 16 A mouse jumps off from the 15th floor of a high rise building and lands 12 m from the building Assume that each floor is of 3 m height The horizontal speec with which the mouse jumps is closest to a zero c 10 km h b 5 km h d 15 km h

First overtone frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe Further nth harmonic of closed organ pipe is also equal to the mth harmonic of open pipe where n and m are ferat fick

When a car is at rest its driver sees rain drops falling on it vertically When driving the car with speed v he sees that rain drops coming at an angle 60 from the horizontal On further increasing the speed of the car to 1 B v this angle changes to 45 The value of B is close to A 0 41 B 0 50 C 0 73 D 0 37

A particle is moving along the x axis under the influence of a force given by F 5x 15 At t 0 the particle is located at x 6 and is having zero velocity It takes 0 5 seconds to reach the origin x 0 for the first time The equation of motion of the particle can be represented by 1 x 3 3 cos t 2 x 3 cos t 3 x 3 3 sin t 4 x 3 3 cos 2 t

A body A is moving along negative x axis and another body B is moving along positive y axis as shown with constant velocity An observer is sitting on body A 400m For VB 10 m sec 1 B VB 300m VA 10 m sec A X Question Type Multiple Correct Type When distance between A and B is minimum particle B has negative y coordinate When distance between A and B is 2 minimum particle B has positive y coordinate 3 Particle will collide

The 800 Kg car travels over the hill having the shape of a parabola When the car is at point A it is traveling at 9 m s and increasing its speed at 3 m s Determine both the resultant normal force and the resultant frictional force that all the wheels of the car exert on the road at this instant Neglect the size of the car 20 1 6400 A X

of the 7 Two buses started simultaneously towards each other from towns A and B which are 480 km apart It took the first bus travelling from A to B eight hours to cover the distance and the second bus travelling from B to A ten hours Determine when the buses will meet after starting and at what distance from A Ang Ah 26 7 min 266 7 kml

25 An alpha particle the nucleus of helium atom with charge 2 is accelerated and moves in a vacuum tube with kinetic energy 10 MeV It passes through a uniform magnetic field of 1 88 T and traces a circular path of radius 24 6 cm Obtain the mass of the alpha particle 1 eV 1 6 x 10 19 J charge of electron 1 6 x 10 1 C

18 in supersonic flight at an altitude h At what smallest distance a along the horizontal from the observer on the ground is there a point from which the sound emitted by the airplane motors reaches to the observer earlier than sound emitted by plane when it is at point A that is directly above the observer u velocity of airplane v velocity of sound S A a B a 2 3 V 1 h h 1 a A h 0 C not possible for any real value of a

In a potentiometer experiment a wire of length 10 m having resistance 2 22 m is connected with a cell of 5 V 1 22 and an unknown resistor R If potential gradient of wire is 2 mV cm then value of Ris 1 30 92 3 299 2 39 4 50 Q

A shot is fired with velocity 2gh horizontally h m above the top of a mountain which is in the form of hemisphere of radius r The point on the mountain which can be reached by the shot is at a distance measured in a straight line from top of the mountain A r r 4rh B r r 4rh C r r 4rh D r r 2rh

Questions 14 16 I A ball of mass 2 0 kg is thrown vertically upward from the top of a building The ball s velocity v is given as a function of time by the equation v 1 R St where R 5 The positive direction is upward m s and S 10 m s 14 What is the ball s acceleration at time 1 1 s A 10 m s 5 m s 0 5 m s 10 m s B C D E 15 At what time does the ball reach its maximum height above the building chase by A 0 2 s B 0 4 s C 0 5 s D 1 0 s E 2 0 s 16 If the ball reaches the ground at t 2 0 s what is the height of the building A 5 m B 10 m PO

A particle is released from a height s At certain height its kinetic energy is three times its potential energy The height and speed of the particle at that instant are respectively A C D s 3gs 4 2 it 2 3gs 2 3gs 2 3gs 2

The displacement of a particle moving in a straight line depends on time t as x at t yt 8 The ratio of its initial acceleration to its initial velocity depends A B C D only on a only on a and B only on and y only on a and y

The water droplets fall at regular interval from a tap 5m above the ground The third drop is leaving the tap at the instant the first drop touches the ground How far above the ground is the second drop at that instant 1 1 25m 2 2 50m 3 3 75m 4 4 00m

Aboy moving with a velocity of 20kmh along a straight line joining two stationary objects According to him both objects 1 move in the same direction with the same speed of 20km lr 2 move in the different direction with the same speed of 20km lr 3 move towards him 4 remains stationary

The trajectory of a projectile launched from ground is given by the equation y 0 025x 0 5x where x and y are the coordinates of the projectile on a rectangular system of axes Find the angle at which projectile is launched 1 0 tan 0 2 3 0 tan 0 5 2 0 tan 0 4 4 0 tan 0 6

4 A person walking at some speed finds the rain falling vertically If he doubles his speed the rain appears to fall at an angle 45 to the vertical To what angle the rain will appear to fall if he triples his speed

The speed of the earth s rotation about its axis is w Its speed is increased to x times to make the effective acceleration due to gravity equal to zero at the equator Then x is Question Type Single Correct Type 1 1 2 8 5 3 17

As shown in the figure a coil of single turn is wound on a sphere of radius 2R and mass M The plane of the coil is parallel to the inclined plane and lies in the equatorial plane of the sphere Considering the sphere in the rotational equilibrium and the current in the coil as I Determine the magnitude of the magnetic field B B A B C D 2Mg I R Mg sin 0 I R Mg cos 0 I R Mg 21TR 2R 0