Newton's law of motion Questions and Answers

Two identical spheres of radii 10 cm each are placed between two rigid vertical walls as shown The spacing between the walls is 36 cm Then the force of contact between the two spheres if the weight of each is Wis en n 1 1 67 W 2 1 25 W 3 1 33 W 4 0 75 W bris pa DE

2 Atwood Machine Consider a massless string going over a frictionless pulley Blocks of masses m and m are attached at the ends of the string Such a system is called Atwood machine Find the acceleration of the blocks and tension in the string

Example 2 7 The forces 20 N 30 N 40 N 50 N and 60 N are acting at one of the angular points of a regular hexagon towards the other five angular points taken in order Find the magnitude and direction of the resultant force of given forces is shown in Fig 2 5

10 m whirling in a circular path in a 3 vertical plane The ratio of maximum tension to the minimum tension in the string is 4 If g is taken to be 10 ms 2 the speed of the stone at the highest point of the circle is of length L 1 a 10 ms c 10 3 ms 1 b 5 2 ms 1 d 20 ms 1

Two masses of 10 kg and 20 kg respectively are 8 connected by a massless spring as shown A force of 100 N is applied on 20 kg and at some instant its acceleration is 6 m s What is the acceleration of 10 kg mass 10 Smooth 1 1 m s 2 3 4 m s 2 20 2 2 ms 4 1 8 m s 6 m s F 100 N

19 An inclined plane makes an angle 0 45 with horizontal A stone is projected normally from the inclined plane with speed u m s at t 0 s X and Y axes are drawn from point of projection along and normal to inclined plane as shown in figure The length of incline is sufficient for stone to land on it and neglect air friction Match the statements given in Column I with the results in Column II g in column II is acceleration due to gravity XK yk 0 45 Column I A The instant of time at which velocity of stone is parallel to X axis P 2 2u g Column II CENTERS MUMBAI DELHI AKOLA LUCKNOW NASHIK PUNE NAGPUR BOKARO DUBAI B The instant of time at which velocity of stone makes an angle 0 45 Q 2u with positive X axis in clockwise direction g C The instant of time till which starting from 1 0 component of R displacement along X axis becomes half the range on inclined plane is D Time of flight on inclined plane is TS 2u g

A man standing inside a moving lift appears to be with respect to woman then the woman must be standing O O O Inside the same Inside the different lift with same velocit Standing on the ground

4 Three forces acting on a body are shown in the figure To have the resultant force only along the y direction the magnitude of the minimum additional force needed is YA 4N IN 30 2N A EN B 3N C 0 5N D L SN

A block rests on a rough inclined plane making an angle of 30 with the horizontal The coefficient of static friction between the block and the plane is 0 8 If the fric tional force on the block is 12N the mass of the block in kg is take g 10 m s

7 Assertion A A falling object facing air resistance during the fall does not obey law of conservation of energy Reason R The general law of conservation of energy is true for all forces and for any kind of transformation between different forms of energy

23 A ball is thrown from a field with a speed of 12 0m s at an angle of 45 with the horizontal At what distance will it hit the field again Take g 10 0 m s a 10 m b 14 4 m c 16 4 m d 18 4 m

System sho g 10 m s figure 4 kg 30 0 5 kg he following statements is are false A Magnitude of acceleration of each block is 3 m s B Tension in the cord A is 6 5 N C Tension in the cord B is 8 N D Difference of magnitudes of tensions in both the cord is 1 5 N Space for Rough Work 0 5kg

Q 36 A solid cylinder of mass M and raidus R is held in a horizontal position Two string are wound round the cylinder As the string gets un wound Find the tension in the string in the cylinder Option 1 Mg 2 Option 2 Mq 6 Option 3 Mg 4 Option 4 Mg 3

32 CAREER INSTITUTE KOTA HAJASTHAN Two forces of 5 N and 12 N simultaneously act 32 5N on a particle The net force on the particle is a A 17 N A 17 N B 12 N B 12 N C 13 N C 13 N D 7 N s F D 7 N Fnet 17 N net 17 N Nurture Course All Phase 21 06 2020 12 Nisan la legal B

Nurture Course 10 05 2020 8 In a particular system the unit of length mass and time are choosen to be 100 cm 20 g and 0 1 s respectively The unit of momentum in this system will be equal to 1 0 02 kg m s 3 20 kg m s 2 0 2 kg m s 4 200 kg m s

A man stands on a scale in an elevator that has an upward acceleration a The scale reads 902 N When he picks up a 20 kg box the scale reads 1220 N 1 Find The mass of the man mman 2 74 2 The weight of the man man kg Submit Help N Submit Help

In the arrangement shown angle 9 the tension T in rope AB in equilibrium are g 10 m s T B 90 30kg A 0 37 T 500 N B 0 45 T 300 N C 0 53 T 500 N D 0 60 T 400 N 40kg

Two pulleys smooth and weightless carry two blocks M and M as shown in figure M 4 M The system is at rest at t 0 The acceleration of mass M is a when the system is released Then the acceleration of M will be 1 8a 2 40 O M 20 cm 212 M

A mass point glides without friction on a cycloid which is given by x a 9 sin 9 and y a 1 cos 9 with 0 9 2 Determine a the Lagrangian and b the equation of motion c Solve the equation of motion

In the given figure m m 10 kg m3 5kg F 30 N All the surfaces are smooth Then F m m 0 30 A Normal force between m and m is zero B Tension in the string is 50N C Acceleration of m is 2 m s in downward direction D m m will move together m

A light string is wrapped round a cylindrical log of wood which is placed on a horizontal surface with it axis vertical and it is pulled with a constant force F as shown in the figure Friction is absent everywhere A Tension T in the string increases with increase in B Tension T in the string decreases with increase in C Tension T F if D Tension T Fif0 T 4 F

Two blocks A and B are connected by a light string as shown in the figure The force exerted by the string on the block B is 1 20 N 2 15 N 3 12 N 4 8 N A 3kg Smooth B 2kg F 20 N 77

Two blocks of masses 2 0 kg and 3 0 kg are connected by light inextensible string The string passes over an ideal pulley pivoted to a fixed axel on a smooth incline plane as shown in the figure When the blocks are released find magnitude of their accelerations g 10 m s 30 3 kg 2 kg

See the diagrams carefully in Column I and match each with the obeying relation s in column II The is massless inextensible and pulley is frictionless in each case a g 3 m mass of block T tensio given string apulley acceleration of movable pulley in each case acceleration due to gravity is g B Column I H m TH a m m mmmmm m wwwwwwww T T a P R Column II Qapulley a T ablock a T mg Force on fixed support T 3 2 mg None of these

2 The figure shows a horizontal force acting on a block of mass m on an inclined plane angle What is the normal reaction N on the block a mgsin0 Fcos0 b mgsin0 Fcose c mgcos0 Fsin0 37

Single Correct Answer Type 7 Q 3 M 1 1 A small Block A is released from the top of an incline plane at height of h 512 m All surfaces are frictionless The block collides with the ground inelastically but does not stick to it After collision with the spring it returns back and collides with the incline inelastically but again does not stick to it Find the maximum height in m from the ground attained by block A when it climbs up the incline AN16 R 33 h 512 m 60 mor

Three identical smooth cylinders each of mass m and radius r are resting in equilibrium within a fixed smooth cylinder of radius R only a part of this cylinder has been shown in the fig Find the largest value of R in terms of r for the small cylinders to remain in equilibrium

at Pest relative to the trolley car simultaneously 21 A block of mass M is placed on a horizontal surface and it is tied with an inextensible string to a block of mass as shown in figure Imagine a situation in which the horizontal surface of block M is smooth and its vertical surface is rough with a coefficient of friction Choose the correct values s of F which the blocks M and m remain stationary with respect to M A Mo M m EXTM M M m U mg Bm M M m g M um D none of these Smooth M Mo m Rough H TIZE

A lady moves a suitcase of mass 22 3 kg with frictionless wheels across a horizontal floor by pulling on a cord attached to the suitcase making an angle of 0 46 1 degrees to the horizontal as shown in the diagram If the lady pulls the cord with a force of 16 5 N what is the magnitude of the acceleration of the suitcase in units of m s

Two persons are holding a rope of negligible weight tightly at its ends so that it is horizontal A 15 kg weight is attached to the rope at the mid point which now no longer remains horizontal The minimum tension required to completely straighten the rope is 1 15 kg 2 15 2 kg 3 5 kg 4 Infinitely large or not possible

Q When we jump on a trampoline we bounc e back up Shouldnt we just stand since Ne wton s third law states every action has an e qual and opposite reaction when they act o n two different bodies So according to this I aw shouldn t the forces just cancel out i e t he force we apply on the trampoline and it s reaction force

The figure shows a rod of length 5 m Its ends A and B are restrained to move in horizontal and vertical guides When the end A is 3 m above O it moves at 4 m s The velocity of end B at that instant is 1 2 m s 2 3 m s 3 4 m s 4 0 20 m s VA 3 m 5m B

In the figure shown the horizontal surface is smooth and the strings are inextensible and the massless pulleys are light If the acceleration of block 1 kg is a then acceleration of 3 kg is 3 kg 1 Zero 2 2a 3 NO 4 4 1 kg

15 In the system shown thread is inextensible masses of the thread and that of the pulleys are negligible as compared to the loads to be lifted and friction at the axles of the pulleys is absent Masses of the loads are 1 0 kg and m 2 0 kg Acceleration of free fall is g 10 m s If axle of the pulley A is pulled upwards with a force F 20 N how much acceleration will it acquire m 1 m1 O A m

What is velocity of block when the angle between string and horizontal is 30 as shown in the diagram Massless string 1 VB VP 2 VB 11 3 VB 2vp 2vp 19 4 VB Block V 0 30 Smooth surface

An object has a mass of 5 kg and the net force acting on it is zero Which of the following is are definitely true about the object Warning May contain multiple answers A There are no forces acting on the object B The object is NOT changing direction C The object is at rest D The object s velocity is constant yes zero is a constant

Q 8 The time taken by a block of wood initially at rest to slide down a smooth inclined plane 9 8 mlong angle of inclination is 30 is a sec 30 b 2sec c 4sec d 1sec

Question A ball is dropped from a high rise platform at t 0 starting from rest After 6 seconds another ball is thrown downwards from the same platform with a speed v The two balls meet at t 18s What is the value of v take g 10 m s O O O O 75 m s 55 m s 40 m s 60 m s

B If the block is being pulled by the rope moving with speed v as shown then the horizontal velocity of the block is e 1 V 2 vcos 3 4 cos sin f m

A uniform rod of mass M and length L is in rotational motion without any hinge on a smooth horizontal table Accelerations of its two ends have same magnitude and are shown in the figure Net force acting on the rod is k 2 10 Ma where k is B 53 a 37 Prev 12 Next

Q 14 When a bullet is fired at a target its velocity decreases by half after penetration 30 cm into it The additional thickness it will penetrate before coming to rest is b 40 cm c 10 cm a 30 cm d 50 cm

A man moves a crate of mass 71 7 kg across a horizontal floor at a constant speed by applying a horizontal push as shown in the diagram the coefficient of kinetic friction between the crate and the floor is 0 545 what is the magnitude of the push force in units of newtons hutterstock POR RANGER WHER

Contact Number 9667591930 8527521718 4 oving A block A of mass 7 kg is placed on a frictionless table angle A thread tied to it passes over a frictionless pulley and carries a body B of mass 3 kg at the other end The acceleration of the system is given g 10 ms ge of rated edge g is 1 100 ms 2 A B

13 Three block of masses m M and M are arranged as shown in fig The Two block of a light surfaces are frictionless pulley and strings pulley as are ideal The mass M of the hanging block which will prevent the smaller block m from slipping over the wedge will be 1 2 3 M M m coff 1 M m cot 1 M m coto 1 M m m 15 M If the sys 5 m s the 1 24 N 2 36 N 3 48 N 4 18 N

If 3 equal masses of 1kg as shown in figure are accelerated with an acceleration a 2 m s then the tension T is T 1 kg 1 2N T 1 kg 2 6N T 1 kg 3 4N 4 Insufficient data

A block of mass m is placed on the floor of lift which is moving with velocity v 4t where t is time in second and velocity m s Find the time at which normal force on the block is three times of its weight A 111 1 3g 8 s 2 gs 3 4 g s 4 3q s V

A force of 0 1176 N acts horizontally for 5 s on a 50 g block kept on a floor What is the velocity attained by the block Coefficient of sliding friction between the block and the floor is 0 2 196 cm s 11

Two masses M 5 kg and M 10kg are connected at the ends of an inextensible string passing over a frictionless pulley as shown When the masses are released then the acceleration of the masses will be H M

Two blocks of mass 8 kg and 5 kg are connected by a heavy rope of mass 3 kg Complete system is accelerated upwards by 10 m s as shown in the figure The tension at the point P will be 8kg 1 2 Question Type Single Correct Type 80N P 90N 3kg a a 10 m s 5kg

A pendulum bob is suspended in a Car moving horizontally with acceleration a the angle the string will make with vertical is a To 1 tan 19 2 tan 19 3 sin 19 G H PO A 11 9 1 a 4 cos