Kinematics Questions and Answers

figure If the cannon balls have identical initial speeds which of the following statements is true A Target 2 is hit before target 1 C Both are hit at the same time B Target 1 is hit before target 2 D information is insufficient

39 A particle is projected from a trolley car with a velocity v relative to trolley at an angle 9 with horizontal If the trolley car moves with an accel eration which of the following is same relative to both ground and trolley car 1 Time of flight 3 Range 0 60 2 Horizontal velocity 4 Velocity

Two trains each of length parallel tracks One overtakes the other in 20 s when they are moving in the same direction and crosses the other in 10s when they move in the opposite directions The velocities of the two trains are 1 15 m s 5 m s 3 10 m s 10 m s 2 25 m s 15 m s 4 30 m s 10 m s

36 A man runs at a speed of 5 m s to board a standing bus When he is 50 m behind the door at t 0 the bus moves forward and continues with a constant acceleration of 1m s2 Then the man boards the bus in 10 s boards the bus in 8s boards the bus in 12 s 1 2 25 00 62 3 12 5 4 misses the bus 195 d 2025

You toss a ball straight up in the air At the highest point the ball s velocity and acceleration are zero acceleration is zero but not its velocity velocity is zero and the acceleration is downward

A 73 0 kg ice hockey goalie originally at rest catches a 0 150 kg hockey puck slapped at him at a velocity of 39 0 m s Suppose the goalie and the ice puck have an elastic collision and the puck is reflected back in the direction from which it came What would their final velocities in m s be in this case Assume the original direction of the ice puck toward the goalie is in the positive direction Indicate the direction with the sign of your answer m s m s puck goalle

A steel ball is dropped from a diving platform with an initial velocity of zero The approximate value of the acceleration due to gravity g is 10 m s2 What is the velocity of the ball 0 2 seconds after its release Round the final answer to the nearest whole number 30 m s

An aeroplane is flying horizontally at a height of 10 490 m with a velocity of 360 km h A bag containing ration is to be dropped to the jawans on the ground Calculate time taken by the bag to reach the jawans on ground 1 5 sec 3 15 sec 2 10 sec 4 20 sec forgi 1 5 sec 3 15 sec 490 360 km h e forma 2 10 sec 4 20 sec

Suppose you throw a ball vertically downward with a speed of 10 m s Neglecting air friction what would be the speed of the ball one second later O 9 8 m s 9 8 m s 15 m s 19 8 m s 24 8 m s

A car rounds a curve while maintaining constant speed The correct statement is The acceleration of the car is zero No net force acts on the car The velocity of the car is zero The velocity of the car is constant A net force acts upon the car

A body is projected horizontally with speed 5 m s from height h takes 8 s to reach the ground The time it takes to cover the first one fourth of height is NCERT Pg 79 1 4 s 3 2 s 2 6 s 4 5 s

7 Two perfectly elastic particles A and masses travelling along the line joining them with velocity 15 m s and 10 m s respectively collide Their velocity in m s after the elastic collision will be respectively 1 0 and 25 3 10 and 15 2 5 and 20 4 20 and 5

A projectile is fired from the level ground at a angle 0 above the horizontal The elevation angl a of the highest point as seen from the launc point is related to 0 by the relation 1 tana tan0 2 tana 2tan0 3 tana tan 0 4 tan 9

Here why are we converting it into radians by multiplying with 2pue 3 20 4 22 12 A 12 2 resistor and a 0 21 H inductor are connected in series to an a c source operating at 20 V 50 cycle second The phase angle between current and source voltage is 1 30 2 40 3 80 4 90

A block of mass m is sliding down on an inclined plane of angle of inclination 8 with constant speed v The Force of friction is coefficient of friction between block and plane is mgsine mgcose

30 Motion in plane The position vector of a particle is given by r 2sin nt i 2cos nt Where r is in metre and t is in second Select the incorrect option 1 The acceleration of the particle is non uniform 2 The acceleration of the particle is perpendicular to the plane of motion 3 Particle must be undergoing uniform circular motion 4 The speed of the particle is 2 m s

A particle P at point x y is moving in XY plane with velocity v v i v j If distance from origin at given instant is I then dl dt 0 if xVx yVy 0 0 if Xvx yvy 0 0 if Xvx yvy 0 di 0 if xvx yvy 0 dt

5 69 A particle is projected horizontally with velocity V 2ga along the smooth inside surface of a fixed hollow C hemisphere of inner radius a at the level of the centre O The subsequent motion of the particle is confined between the 5 72 horizontal planes one through the centre and the other at a depth h Find the value of h abou two thro The equ A C 3 2 5 1 2 a B D 3 1 3 5 a a

A particle is being pulled by means of a string as shown in figure The free end is being pulled with constant velocity vo If the ball moves along the hemispherical surface then the velocity of particle at the given position would be cha TANY HJME YG TA A uf i ugndu adg h vyftu ofa gza d A B R C 3 4 Correct Answer v vo sec V Vo V Vo sece 0 2

5 64 Three identical cylinders of radius R are in contact Each cylinder is rotating with angular velocity o A thin belt is moving without sliding on the cylinders Calculate the magnitude of velocity of point P with respect to Q P and Q are two points of belt which are in contact with the cylinder A 2R0 C Ro 2 P 0 2 3 Figure 5 120 0 B Ro D Rw 3 bano

A ship is traveling eastward at 15 km hr At 8 00 A M the ship has a bearing of N30 W from a certain port At 10 00 A M the ship has a bearing of N 45 E from the same port How far was the ship from the port at 8 00 A M

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 constant speed 18 km h in direction A to B notices that a bus goes past him every 20 min in the direction of his motion and every 10 min in the opposite direction If the speed of buses in km h plying between the towns is V then find the value of 18

A particle is projected vertically upwards from ground It traversed equal distance in its 6th second and 9th second of its motion then g 10 m s Maximum height attained is 245 m Velocity of projection is 75 m s Average speed over entire journey is 35 m s Time of flight is 15 s

Three positive charges of equal magnitude q are placed at the vertices of an equilateral triangle of side 1 How can the system of charges be placed in equilibrium by placing a charge Q q 3 2 by placing a charge Q at the centroid of the triangle q 3 3 by placing a charge Q q at a distance from all the three charges 4 by placing a charge Q q above the plane of the triangle at a distance from all the three chorga at the centroid of the triangle

In figure a small block of mass m is kept over a plank of mass M and length All surfaces are frictionless Then M A The acceleration of system m M w r t ground is B The acceleration of m w r t ground is zero C The time taken by m to separate from M is D The time taken by m to separate from M is 28m F 20M m F F m M

24 A stone is dropped from the top of a tower and one second later a second stone is thrown vertically downward with a velocity 20 ms The second stone will overtake the first after travelling a distance of g 10 ms a 13 m 9 1 But the 11 25 m b 15 m d 19 5 m of a tower of h 2

graph correct particle moving along given A t 2sec t t 1 sec A Initially particle is moving in x direction B Acceleration of particle is first negative then positive C Acceleration of particle is constant D At t 2 sec speed is same as initial speed Tollowing

14 INC JR CO SCICO SC N120 ADV 05 07 2021 Single Select Q4 of 60 A body has an eastward velocity of 40ms at t 0 at point O and a westward acceleration of 8 ms 2 The speed of the body is 40 ms again after t 1 O 4 s

A ball of mass m approaches a wall of mass 22 M m with speed 4 m s along the normal to the wall The speed of wall is 1 m s towards the ball The speed of the ball after an elastic collision with the wall is 1 5 m s away from the wall 2 9 m s away from the wall 3 3 m s away from the wall 4 6 m s away from the wall 3 and ar 1 5 2 9 3 3 4 6 1

A particle is projected with velocity 41 9j m s The acceleration in the region is constant and 10 m s The trajectory equation will be 3y x 5x y 9x 5x 3y 9x 5x O 16y 36x 5x

Key Ideas After completing this chapter you shoul Understand the term kinematics 1 3 2 Know the types of motion projectil Define the scalar and vector quantit Understand the basic terms and to c relating to these terms the equations of motion for t 4

13 An automobile starting from rest increases its speed from 0 to v with a con acceleration a runs at this speed for a time and finally comes to rest with cons deceleration a2 If the total distance traveled is s find the total time t required Ans t s v v 2 1 a 1

Figure shows the graph of speed versus time for a moving truck Ratio of distance travelled by truck between t 3 to t 5 seconds to the distance travelled by truck between t 5 to t 7 seconds is v m s B 20 15 10 5 Jc 1 2 3 4 5 6 7 t sec

4 A particle starts from origin and moving along x axis whose v t graph is as shown Choose the CORRECT statement s 10 M ON 8 10 OO 10 A At point L particle is speeding up B At point M particle is moving in positive x direction C At point N particle is slowing down D At point O particle is rest

You are target shooting using a toy gun that fires a small ball at a peed of 15 m s When the gun is fired at an angle of 33 above orizontal the ball hits the bull s eye of a target at the same height as ne gun Then the target distance is halved Y Part A At what angle must you aim the gun to hit the bull s eye in its new position Mathematically there are two solutions to this problem the physically reasonable a the smaller of the two AEO

Figure shows the velocity time v t graph of a particle travelling on a straight road Which of the following statement s are INCORRECT v m s 2 3 t sec A Velocity and acceleration have same sign at point 1 B Particle changes its direction of motion at point 3 C Velocity of car is equal to zero but acceleration is not equal to zero at point 2 D Speed of particle is continously decreasing from point 1 to 3

Tapas shown in the figure there 33 is only one graph for which average velocity over the time interval 0 T can vanish for a suitably chosen T Which one is it 1 2 3 4 Fourse VII VII IX 6092020 0 T P 2 3 Space for Rough Work fog E 1001CMD3008200 Page

22 A particle is in uniform circular motion with speed Vo The change in magnitude of velocity when it covers half of circular path is 1 Vo 12 Zero es Inez 3 2v 4 2 2 If an object an object is moving on a curved path then which of the following physi Time Period is Indepe ndent un sombrizon ta ICC if 29 ation

J A car moving towards north at a speed of 10 m s turns right within 10 s maintaining the same speed Average acceleration of the car during this time interval is m s S W 2 r 1072 TO 2 1 2 IV 3 2 m s S E 4 2 m s N E m s N E 2 misec S E

If velocity v of a particle moving on a straight line as a function of time t is given as v 5 t m s then the distance covered by the particle in first 10 s is Att o s 2 15 m 4 50 m 1 5 m 3 25 m The position time x t graph for a particle moving along x axis is as shown Average speed of the 4 15 Gali star dist mot 1 3

Paragraph for Questions 32 A car starts from rest and accelerates as shown in the accompanying diagram Acceleration in m s 2 6 ALLEN 8 2 4 second 4 8 second Time in seconds At what time would the car be farthest from its 32 original starting position 1 2 second 3 6 second Paragraph for Questions 32 FR FORT REFER Radi Acceleration in m s 4 2 1 2 second 3 6 second 2 4 Time in seconds af fenf fu 2 4 second

3 144 second 4 14 4 second 5km 49 A projectile is thrown at an angle 37 from the vertical The angle of elevation of the highest points of the projectile from point of projection is E n 114

15 A swimmer crosses a river in shortest distance If he tries to swim at 4 km hr maintaining 120 with the downstream then speed of the river is 1 1 km hr 3 3 km hr 16 A man moves on a horizontal road towards east at a speed of 1 km hr and the rain appears to him vertical at a speed of 2 km hr The actual speed of AL CAMERA the rain in km hr is Gor3y VR 2 2 km hr 4 Sin33 21 4 4 km hr 2 km n 2 no 22 2011 08 1

18 An object moves along x axis such that its position varying with time t is given as x 4t t x is in metre and time t in second The distance travelled by the object from t 0 to t 3 s is HD 1 3 m 2 5 m 3 12 m 4 21 m

0 Da A particle is thrown vertically up with initial velocity of 60 m s The distance covered by the particle in first two seconds of descent will be take g 10 m s 1 5 m 3 20 m 2 15 m 4 40 m

A ship A is moving Westwards with a speed of 10 kmh and a ship B 100 km South of A is moving Northwards with a speed of 10 kmh 1 the shortest distance between them is 2 10 3 4 50 3 1 10 2 3 50 2

Two cars A and B are approaching each other head on with speeds 20 m s and 10 m s respectively When their separation is X then A and B start braking at 4 m s and 2m s respectively Minimum value of X to avoid collision is 1 60 m 2 75 m 3 80 m 615150 for 15 Se c

Drops are falling from a tap at a height 0 9 m at regular intervals The fourth drop just starts to fall when the first drop just reaches the ground At that instant the height of second and third drops is respectively 1 0 5 m 0 8 m 3 0 4 m 0 1 m 2 0 3 m 0 1 m 4 0 4 m 0 9 m

Two bodies are dropped in succession from a height at interval of one second The relative velocity of body one with respect to other is where g is the acceleration due to gravity g g 2g x Zero

b Find its velocity at t 2 70 s m s c Find its acceleration at t 2 70 s m s Need Help 6 66 Points Read It DETAILS Master It SERPSE10 2 7 OP 014 0 5 Submissions Used A truck covers 44 0 m in 8 60 s while smoothly slowing down to final speed of 2 00 m s a Find its original speed