# laws of motion class 11 neet questions

*Dear students numericals **problems **of laws of motion class 11 neet questions chapter 5 jee questions aiims important questions have been collected at one place to get you all prepared for your neet, aiims ,jee main, advance exams as well as cbse board exams and other board exams. Visit my nawendu classes youtube channel for more help.*

1. 4 kg mass and 1 kg mass are moving with equal kinetic energies .The ratio of the magnitudes of their momentums is

* Answer- 2:1*

2. The recoil velocity of a 4kg rifle that shoots 0.05kg bullet at speed of 280 m/s is

**Kerala PMT 2004**

Answer- -3.5 m/s

3. A ship of mass $3X{{10}^{7}}$ kg initially at rest is pulled by a force of $5X{{10}^{4}}$ N through a distance of 3 m. Assuming that the resistance due to water is negligible .What will be the speed of the ship?

** MP PMT 2000**

Answer- 0.1m/s

4. A particle of mass 10 kg is moving in a straight line .if its displacement x with time t is given by $x=({{t}^{3}}-2t-10)m$ ,then the force acting on it at the end of 4 second is

CBSE 2001

Answer- 240 N

5. A constant force acts on the body of mass 0.9kg at rest for 10 sec. If the body moves a distance of 250 meter , the magnitude of the force is

** DCE 2001**

Answer- 4.5N

6. A block of mass 60 kg. just slides over a horizontal distance of 0.9 m. If the coefficient of friction between their surfaces is 0.15 then work done against friction will be

Answer- 79.4 J

7. A marble block of mass 2 kg lying on ice when given a velocity 6 m/s is stopped by friction in 10 second. Then the coefficient of friction is

**AIIMS 2012 **

Answer- 0.06

8. A ball of mass 150 gm moving with an acceleration 20 $m/{{s}^{2}}$ is hit by a force, which acts on it for 0.1 sec. The impulsive force is

CBSE PMT1999

Answer-
0.3Ns

9. An ice cart of mass 60 kg rests on a horizontal patch with co-efficient static friction 1/3 assuming that there is no vertical acceleration, find the magnitude of the maximum horizontal force required to move the ice cart

(g=9.8$m/{{s}^{2}}$)

** Kerala PET 2004**

Answer- 196 N

10. A body of mass ‘a’ moving with a velocity ‘b’ strikes a body of mass ‘c’ and gets embedded into it. The velocity of the system after collision is

** AFMC 2000**

Answer- ab/a+c

11.A body of mass 4.975kg is lying on the frictionless floor. A mass of 25 gm moving with 400 m/s strikes the mass and gets embedded in it. The velocity of the body combined after collision is

**AFMC 2006 **

Answer- 2m/s

12. A bullet of mass 10 g moving horizontal with a velocity of 400m/s strikes a wood block of mass 2 kg which is suspended by light inextensible string of length 5 m. As a result the center of gravity of the block found to rise a vertical distance of 10 cm. The speed of the bullet after it emerges of horizontally from the block will be

** NEET 2016 **

Answer- 120 m/s

13.Consider car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of static friction between the tyres and the road is 0.5, the shortest distance in which the car can be stopped is (taking g=10 $m/{{s}^{2}}$ )

** CBSE-PMT 1992 **

Answer- 40m

14. If cyclist moving with a speed of 4.9 m/s on a level road can take sharp circular turn of radius 4 m, then coefficient of friction between the cycle tyre and the road is

** AFMC 2001 **

Answer- 0.61

15. A car of mass 1000 kg negotiates a banked curve of radius 90 m on a frictionless road. If the banking angle is 45 degree ,the speed of the car is

**CBSE AIPMT 2012**

Answer- 30 m/s

*16*. A Cyclist moves in a circular track of radius 100m. If the coefficient of friction is 0.2 then the maximum speed with which the cyclist can take a turn without leading inwards, is

** AFMC 1988 **

Answer- 14m/s

17. A cyclist is moving in a circular track of radius 80 m with velocity 36km/h. He has to lean from the vertical approximately through an angle (g=10$m/{{s}^{2}}$)

**Kerala PET 2004**

Answer- $ta{{n}^{-1}}\left( \frac{1}{8} \right)$

18. A car is negotiating a curved road of radius R. The road is banked at angle $\theta $ . The coefficient of friction between the tyres of the car and the road is ${{\mu }_{s}}$ . The maximum safe velocity on this road is

**NEET 2016 **

Answer- $\sqrt{gR\left( \frac{{{\mu }_{s}}+\tan \theta }{1-{{\mu }_{s}}\tan \theta } \right)}$

19. A bomb of 12kg explodes into two pieces of mass 4 kg and 8 kg .The velocity of 8 kg mass is 6m/s. The kinetic energy of the other is

Answer- 288 J

20. A body of mass 5 kg. explodes at rest into three fragments with masses in the ratio 1:1:3. The fragments with equal masses fly in mutually perpendicular directions with speeds of 21 m/s. The Velocity of heaviest fragment in m/s will be

Answer- \[7\sqrt{2}\]

21. A body of mass M, at rest explodes into three pieces. Two of which of masses M/4 each are thrown off in perpendicular directions with velocity of 3 m/s and 4m/s respectively. The third piece will be thrown off with a velocity of .

** AFMC 2001 **

Answer- 2.5 m/s

22. In the figure given the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t= 2s is

** AIIMS 2005 **

Answer- -0.2 kgm/s

23. The force F acting on a particle of mass m is indicated by the force- time graph shown below. The change in momentum of the particle over the time interval from 0 to 8 second is

**CBSE AIPMT 2014 **

Answer- 12 N-s

24. If a block is moving up at ${{30}^{\circ }}$ with velocity 5m/s, stops after 0.5 sec then coefficient of friction is

** CPMT 1995, AFMC 2000 **

Answer- 0.6

25. Starting from rest, a body slides down a ${{45}^{\circ }}$inclined plane is twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is

** CBSE PMT-1988 **

Answer- 0.75

26. A block at rest slides down a smooth inclined plane which makes an angle 60 degree with the vertical and it reaches the ground in ${{t}_{1}}$ second. Another block is dropped vertically from the same point and reaches the ground in ${{t}_{2}}$ second .then the ratio of ${{t}_{1}}:{{t}_{2}}$ is

** KERALA CEE 2011**

Answer- 2:1

27. A smooth block is released from rest on a ${{45}^{\circ }}$ inclined and then slides a distance d. The time taken to slide is n times as much to slide on rough inclined than on a smooth inclined. The coefficient of friction is

** AIIMS 2008 **

Answer- ${{\mu }_{k}}=1-\frac{1}{{{n}^{2}}}$

28. A block of mass 2kg rests on a rough inclined plane making an angle of 30 degree with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The frictional force on the block is

** IIT 1980 ,2 M **

Answer- 9.8 N

29. A block of mass 0.1 kg is held against a wall applying a horizontal force of 5N on the block . If the coefficient of friction between block and the wall is 0.5 ,the magnitude of the friction force acting on the block is

IIT 1994, 1M

Answer- 20 N

30. What is the maximum value of the force F such that the block shown in the arrangement , does not move ?

IIT 2003, 2M

Answer- 20 N

31. A block of mass 1 kg lie on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is 0.6 . If the acceleration of the truck is 5 \[m/{{s}^{2}}\] , the friction force acting on the block is

IIT 1984, 2M

Answer- 5 N

32. The upper half of an inclined plane of inclination $\theta $ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom ,if the coefficient of friction between the block and the lower half of the plane is given by

** NEET 2013 **

Answer – 2tan$\theta $

33. A particle is projected up a rough inclined plane of inclination $\theta $ and friction coefficient $\mu $ . If the time of ascent is half of the time of descent ,the friction coefficient $\mu $ is equal to

** AIIMS 2005**

Answer- $\frac{3}{5}\tan \theta $

34. Three blocks A ,B and C of masses 4kg ,2kg and 1kg respectively ,are in contact on a frictionless surface , as shown. If a force of 14 N is applied on the 4 kg block ,then the contact force between A and B is

**CBSE AIPMT 2015 ,WB JEE 2012 **

Answer- 6N

35. A 600 kg rocket is set for a vertical firing. If the exhaust speed is 1000 m/s, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

**CBSE-PMT 1990 **

Answer- 6 kg/s

36. A body of mass M hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is

**CBSE-PMT 2011 **

Answer- 2mv

37. A 1 kg. particle strikes a wall with a velocity 1m/s at an angle 30 degree and reflects at the same wall in 0.1 second then the force will be

** AIIMS 1999 **

Answer- $10\sqrt{3}$

38. A 150 g tennis ball coming at a speed of 40 m/s is hit straight back by a bat to a speed of 60 m/s. the magnitude of the average force F on the ball, when it is in contact for 5 ms is ** AIIMS 2011 **

Answer- 3000 N

39. A rigid ball of mass m strikes a rigid wall at ${{60}^{\circ }}$ and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be

**NEET 2016 **

Answer- mv

40.The mass of a lift is 2000 kg. When the tension is the supporting cable is 28000 N, then the acceleration is

**CBSE-PMT 2009 **

Answer- 4$m/{{s}^{2}}$

41.The mass of a lift is 500 kg .What will be tension in its cable when it is going up with an acceleration of 2$m/{{s}^{2}}$ .

** MP PMT 2000**

Answer- 5900N

42. A man weighs 80 kg . He stands on a weighing scale in the lift, which is moving upward with uniform acceleration 5 $m/{{s}^{2}}$ .What would be the reading on the scale (g=10$m/{{s}^{2}}$)

**CBSE PMT 2003**

Answer- 1200 N

43.A man of mass 60 kg. records his weight on a weighing machine placed inside a lift. The ratio of weight of man recorded when lift ascending up with uniform speed of 2m/s to when it is descending down with uniform speed of 4m/s

**AIIMS 2007 **

Answer- 1

44.A person of mass 60 kg is inside a lift of mass 940 kg and presses the button on control panel. The lift starts moving upwards with an acceleration 1.0 $m/{{s}^{2}}$ . If g=10 $m/{{s}^{2}}$ , the tension in the supporting cable is

** CBSE-PMT 2011 **

Answer-
11000N

45. A lift is moving in upward direction . Total mass of the lift and the passengers is 1600 kg . The variation of the velocity of the lift is as shown in the figure . The tension in the rope at t= 8 second will be

**AIIMS
2018 **

Answer- 11200 N

46. Two bodies of masses 8kg and 12kg are tied to the both ends of a light string went over a pulley. If the bodies are released then find acceleration of the bodies and tension in the string.

** NCERT **

Answer- a= 1.96 $m/{{s}^{2}}$ ,T= 94 N

47.A light string passing over a smooth light pulley connects two blocks of masses m1 and m2 (vertically) if the acceleration of system is g/8, then the ratio of masses is

** CBSE-PMT 2010 **

Answer- 9:7

48. Two bodies of mass ${{m}_{1}}$ and ${{m}_{2}}$ are connected by a light string passing over a smooth light fixed pulley .The acceleration of the system is g/7.The ratio of their masses is

Answer- 4:3

49. A system consists of three masses ${{m}_{1}},{{m}_{2}},{{m}_{3}}$ connected by a string passing over a pulley P. The mass ${{m}_{1}}$ hangs freely and ${{m}_{2}}$ and ${{m}_{3}}$ are on a rough horizontal table ( the coefficient of friction is $\mu $ ) .The pulley is frictionless and of negligible mass. The downward acceleration of mass ${{m}_{1}}$ is

(Assume ${{m}_{1}}={{m}_{2}}={{m}_{3}}=m$ )

** CBSE AIPMT 2014
, AIIMS 2001**

Answer- $\frac{g\left( 1-2\mu \right)}{3}$

50. System shown in the figure in equilibrium and at rest. The spring and string are massless, now the string is cut. The acceleration of mass 2m and m just after the string is cut will be

IIT 2006, 3M

Answer- g/2 upwards , g downwards

51. Consider the situation as shown in the figure .The coefficient of friction between the blocks is 0.5. The acceleration of the lower block is

** AIIMS 2005 **

Answer- $1m/{{s}^{2}}$

52. A body of mass 40 kg resting on rough horizontal surface is subjected to a force P which is just enough to start the motion of the body. If \[{{\mu }_{s}}=0.5,{{\mu }_{k}}=0.4,g=10m/{{s}^{2}}\] and force P is continuously applied on the body, then acceleration of the body is

**AIIMS 2015 **

Answer- $1m/{{s}^{2}}$

53. A particle is moving along a circular path with a constant speed of 10 m/s. What is the magnitude of the change in velocity of the particle , when it moves through an angle of ${{60}^{\circ }}$ around the center of the circle ?

IIT 2019 Main,10 Jan I

Answer- 10 m/s

54. A ball of mass (m) 0.5 kg is attached to the end of a string having length (l) 0.5 m. The ball is rotated on a horizontal circular path about vertical axis. The maximum tension that the string can bear is 324 N. The maximum possible value of angular velocity of ball ( in rad/sec) is

IIT 2011

Answer- 36

55. A car is moving in a circular horizontal track of radius 10 m when a constant speed of 10 m/s. A plumb bob is suspended from the roof of the car by a light rigid rod .The angle made by the rod with the vertical is

IIT 1992, 2M

Answer- ${{45}^{\circ }}$

56. A mass of 10 kg is suspended vertically by a rope from the roof . When a horizontal force is applied on the mass ,the rope deviated at an angle of 45 degree at roof point. If the suspended mass is at equilibrium , magnitude of the force applied is

**IIT 2019 MAIN ,9
JAN II **

Answer- 100 N

57. A block kept on a rough inclined plane, as shown in the figure, remains at rest upto a maximum force 2 N down the inclined plane .The maximum external force up the inclined plane that does not move the block is 10 N .The coefficient of static friction between the block and the plane is (take g=10 $m/{{s}^{2}}$ )

** IIT 2019 MAIN
,12 JAN I **

Answer- $\frac{\sqrt{3}}{2}$

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