Newton's law of motion Questions and Answers

A long uniform solid cylinder of radius r and resistivity p carries current I along its length which is uniformly distributed throughout its cross sectional area Two long hollow cylinder B and C of radi 8 r and 64 r surrounds the solid cylinder The surface of all cylinder A B and C are perfectly black At equilibrium the temperature of B is 400 K or 10 8 Take P S I unit o Stefan s constant 8 r A B Then at equilibrium 64 r C

The upper half of an inclined plane with inclination o is perfectly smooth while the lower halfis rough A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is given by 2020 a 2 cos p b 2 sin o c tan o d 2 tan o

In the figure given above the pulley moves upward with a velocity 5 m s and block A moves downward with a velocity 2 m s What will be the velocity of block B All the velocities are w r t the observer at the ground 2m s A P B 5m s A 3 m s downward B 12 m s downward c 12 m s upward

3 55 A parachutist after bailing out falls 50 m without friction When parachute opens it decelerates at 2 2 ms 2 At what height did he bail out S la 293 m c 91 m b 111m d 182 m

0 Calculate the tension in the string shown in figure 5 E13 The pulley and the string are light and all surfaces are frictionless Take g 10 m s In case of fruit Je 0 2 aums T 1 kg Figure 5 E13 1 kg

A shell is fired from a cannon with velocity v m s at an angle 0 with the horizontal direction At the highest point in its path it explodes into two pieces of equal mass One of the pieces retraces its path to the cannon and the speed in m s of the other piece immediately after the explosion is 1 3vcos 0 2 2vcos0 3 3v 2 Cos 0 4 3v cos 0

ding with an acc celerat 3 What will be the time period of a simple pendulum suspended from ceiling if its time period in stationary lift is T 1 3 2 28 2 4 T 3 23 T

A car travels with constant speed on a circular road on level ground In the figure shown F is the force of air resistance on the car Which of the other forces best represent the horizontal force of the air road on the car s tires A FA C F B FB D F F

Two types of balances the beam balance and the spring balance are commonly used for measuring weight at shops If we are at the moon we can continue to use 1 Only the beam type balance without any change 2 Only the spring balance without any change 3 both the balances without any change 4 Neither of the two balances without

A block og mass 5 kg is on rough horizontal surface and is at rest nw a force of 24 N is imparted to it with negligible impulse if the coefficient of kinetic friction is 0 4 and g 9 8m s2 then the acceleration of block is

3 0 In figure shown the graph shows the variation of a unidirectional force F acting on a body of mass 10kg in gravity free space with time t The velocity of the body at t 0 is zero Area under F 1 curve gives change in momentum F N 20 10 10 15 impulse or 25 30 change monsentim t s The velocity of the body at t 30 s is A 30 m s B 20 m s C 40 m s The power of the force at t 12 s is Power force x velocity A 225 0 W B 217 6 W C 226 7 W The average acceleration of the body from t 0 tot 15 s is A 1 25 m s B 4 7 m s C 5 6 m s The change in momentum of the body between the time t 10s to 15 s is A 100 kg m s B 75 kg m s C 125 kg m s D none D none D none D 7 6 m s

acceleration of block is 4017 1 4 m s2 121 1 2m s acceleration of 2 m s2 then m s o 1kg 2 2 m s 4 8 m s

starts flying upwards with an acceleration 82 in an air tight cage then the boy will feel the weight of the cage 1 Unchanged 3 Increased 2 Reduced 4 Nothing can be said

Que A bead can slide on a smooth straight wire and a particle of mass m attached to the bead by a light string taut and as shown in figure and then let fall If the bead has a mass 2 m then when the string make an angle with the wire find the speed of the bead and the distance it slide upto this Instant 2m L JAN

of mass m is placed on a smooth wedge of inclination 0 The whole system is accelerated horizontally so that the block does not slip on the wedge The force exerted by the wedge on the block g is acceleration due to gravity will be 1 mg sine 2 mg 3 mg cos0 4 mg cose

A heavy string of mass m hangs between two fixed points A and B at the same level The tangents to the string at A and B are at an angle 0 with horizontal as shown in the figure The tension of the string at its lowest point is A C mg 2 sin 0 mg 2tane 6 D mg 2cos mg 2 cot A ke 0

The position time graph of a particle of mass 0 25 kg is shown below The magnitude of each impulse received by the particle is Position cm 2 M 4 6 2 5 x 10 3 Ns 5 x 10 4 Ns O 5 x 10 Ns 8 10 Time s 12 14 16

4 1 145 N 6 The system shown in the figure is in equilibrium The maximum value of W so that the maximum value of static frictional force on 100 kg body is 450 N will be 100kg T 1 100 N 45 W 2 250 N

In the system shown in figure m m system is held at rest by thread T Just after the thread Tis cut m m T Acceleration of m will be zero Acceleration of m will be upward Acceleration of m will be m m m m 2 g Magnitude of acceleration of two block will ho non zoro and unoqual

11 In the diagram shown when the string under the mass M is cut then block M rises up with 1 acceleration g 4 If we had cut the string under M2 then the block M would have risen with acceleration g 2 Find out the value of M M 0 0 Your options are 2 3 4 5 6 Initially tension is present in all the strings M o M

The wedge is acted upon by a force so that block is at rest relative to wedge All surfaces are smooth Ratio of force F to the magnitude of contact force between block and wedge is 1 3 1 F B 2 3 2m m 30 2 3 1 4 3 2

In the diagram if the vertical displacement of the rod B in the upward direction is H and the horizontal displacement of wedge 1 in the forward horizontal direction is X what is the vertical upward displacement of the A WEDGE 1 ROD A a A Xtana Htan B Xtana H C Xtana Hcot D Xcota Htan WEDGE 2 ROD B

If two spheres A and B each having mass M are moving along same line with same speed in opposite direction collide head on elastically then A Bayer coax and a faufa A velocity of A before collision and after collision is same A 4 a dg CHA B velocity of B before collision and after collision is same B TE 3 DG GA C after collision the velocities of both A and B are same D after collision the velocities of both A and B are different E SHI

Q If two spheres A and B each having mass M are moving along same line with same speed in opposite direction collide head on elastically then feen fazla bir quye coax and at A velocity of A before collision and after collision is same AT CA B velocity of B before collision and after collision is same fafa B 46 3 DIG B C after collision the velocities of both A and B are same D after collision the velocities of both A and B are different A Your Answer D

3 Two pith balls of mass 10 mg each are suspended by two threads from the same support are charged identically They move apart by 0 08 m and threads make an angle 60 with each other Find the charge on each pith ball 6 33 nC Tre

I am not able to solve the both ques tions The two questions are related to each other that s why I am upload ing the the both question in one pict ure 40 Consider the shown arrangement Assume all surfaces to be smooth If N represents magnitudes of normal reaction between block and wedge then acceleration of M along horizontal is equal to b c d N sin 0 M N cos 0 M N sin 0 M N sin 0 m M M m 0 along ve X axis along ve X axis a N cos 0 Mg c N cos 0 Mg along ve X axis along ve X axis 41 In the above problem normal reaction between ground and wedge will have magnitude equal to b N cos 0 Mg mg d N sin 0 Mg mg

A uniform disc of mass m and radius R is held by two strings S and S of same length e as shown in figure Young s modulus and cross sectional area of both strings are Y and A Then A In equilibrium extension in the string S is mge 2YA B Immediately after cutting the string S extension in the string S is mgl 3YA C Immediately after cutting the string S extension in the string S is mg YA 5 m g e D Magnitude of change in elastic potential energy in string S is 72 YA S r

A small block of mass 1 kg is placed at a distance 4 m from open end on a truck starting from rest with constant acceleration of 4 m s if Us 0 3 and Uk 0 2 between truck block Find KE of block in joule w r t truck when it is about to fall 1kg 4m

Two springs each have spring constant k and relaxed length They are both stretched a distance and attached to a mass m and two walls as shown At a given instant the right spring constant T m 4 Vk is somehow magically changed to 3k the relaxed length remains At a time t what is m s position Ignore gravity in this problem A At a distance of 30 from the rear wall and at a distance of from the front wall B At a distance off from the rear wall and at a distance of 3f from the front wall C At a distance of 20 from the rear wall and the front wall D At a distance of 2 5 from the rear wall and at a distance of 1 5 from the front wall 20 m 20 later

A small ball is thrown from foot of a wall with the minimum possible velocity to hit a bulb B on the ground a distance L away from the wall Find expression for height h of shadow of the ball on the wall as a y

3 AB is a cable and BCD is a solid rigid member it does not bend If the member BCD is pinned at point E and is supported by a cable AB at point B The member AB is pinned to the wall at point A The member AB is made of steel cable with a diameter of 1 inch Assume that point B moves down the amount cable AB deforms Find the stress in cable AB and the movement of point C answers A 40 000 lb Dx 32 000 lb Dy 4 000 lb answers Stress AB 50 930 psi Movement of C 109 rof BC 8 ft 370 16 000 lbs C 12 000 lbs 8 ft

A layer of glycerine of thickness 1 mm is present between a large surface area and a small surface area of 0 1 m With what force the small surface is to be pulled so that it can move with a velocity of 1 m s Given that coefficient of viscosity 0 07 kg m s 1 70 N 2 7 N 3 700 N 4 0 70 N

With what acceleration a shown the elevator descends so that the block of mass M exerts a Mg force of on the weighing machine g acceleration due to gravity 10 M weighing machine a

A solid cube of mass 5kg is placed on a rough horizontal surface in xy plane as shown The friction coefficient between the surface and the cube is 0 4 An external force F 61 81 20kN is applied on the cube use g 10m s 4 The block starts slipping over the surface The friction force on the cube by the surface is 10N The friction force acts in xy plane at angle 127 with the positive x axis in clockwise direction

In the figure shown all the surfaces are smooth All the blocks A B and C are movable x axis is horizontal and y axis is vertical as shown Just after the system is released from the position as shown M X wwwwww horizontal surface A Acceleration of A relative to ground is in negative y direction B Acceleration of A relative to B is along x axis C The horizontal acceleration of B relative to ground is along x axis D The acceleration of B relative to ground is directed along the inclined surface of C is greater than gsin0

A man holds a mass M by means of the multiple pulley arrangement shown in the figure If all sections of the rope are regarded as vertical the pulleys are very light and friction is negligible He wishes to raise the mass through a height h He pulls down the rope through distance L L Then is equal to h M

2 Which of these statement s is are true when observed from inertial refrence frame A An object can have zero acceleration and be at rest B An object can have non zero acceleration and be at instantaneous rest C An object can have zero acceleration and be in motion D An object can have constant velocity and move on curved path Question umorical Ang 60 MON

As shown in the figure a hemispherical bowl is placed horizontally on a table Point O is the centre of the hemisphere The edge and the surface of the bowl are smooth A particle of mass m is placed in a bowl and is tied to a string with negligible mass The other end of the string is tied to another particle of mass m hanging outside the bowl When the system is in equilibrium the line joining the particle m and Point I makes an angle a 60 with the horizontal Find the ratio m m A 0 71 B 0 87 a m C 1 15 m D 1 73

A block of mass M is placed on a horizontal surface and it is tied with an inextensible string to a block of mass m as shown in figure A mass mo is also placed on M mo M m If there is no friction between any two surfaces then at the instance m is released from rest Clear Response the downward acceleration of the block m mg is m mo M the acceleration of m is zero

A rocket of mass 6000 kg is set for vertical firing If the exhaust speed be 1 km s how much gas must be ejected to give the rocket an upward acceleration of 20 ms 2 Take g 10 ms 2 1 45 kg s 3 120 kg s 2 90 kg s 4 180 kg s

In the figure shown string is massless and inextensible Pulley and spring are massless When the string is cut ratio of acceleration of block 2 to acceleration of block 1 is 1 2m mm 2 m

A plank inclined at an angle of a to the horizontal lies on two supports A and B see figure over which it can slip without friction under the action of its own weight Mg With what acceleration and in what direction should a man of mass m move along the plank so that it should not slip I A a B A the man should move down the plank B the acceleration of the man should be gsin a 1 M C the acceleration of the man should be g sin a 1 D the man should move up the plank sina 1 M m

A rigid body can be hinged about any point on the x axis When it is hinged such that the hinge is at x the moment inertia is given by 1 2x 12x 27 the x co ordinate of centre of mass is 1 2 3 5 2 4 4 3

Which of the following statement is absolutely correct about mass a More the mass of a body connected with spring balance more will be the elongation in spring balance b More the mass of body kept in one pan of beam balance more the mass has to be kept on the other pan to keep beam horizontal c More the mass of a body lesser will be its acceleration for a given force d All of the above

A particle is moving along the path given by y c 6 t6 where c is a positive constant The relation between the acceleration a and the velocity v of the particle at t 5 s is O O O ya v a v a 5v

A particle travels half of total distance with speed V and next half with speed V along a straight line Find out the average speed of the particle O O O Vi V V2 2 V V 2 V V V V V V V V None of these

u are noptii a grouve as ouw us gure below 500 N 800 N 30 A 200 N 0 2 for all rubbing surfaces 150 Q3 Determine the force F required to move the block A up the plane 19 Weightless wedge F 10

A spherical cloud of dust in space has a uniform density po and a radius Ro The gravitational acceleration of free fall at the surface of the cloud due to the mass of the cloud is go A process occurs occurs heat expansion that causes the cloud to suddenly grow to a radius 2R0 while maintaining a uniform but not constant density The gravitational acceleration of free fall at a point Ro away from the center of the cloud due to the mass of the cloud is now

110 In the figure shown lower pulley is free to move in vertical direction only Block A is given a uniform velocity u as shown what is velocity of block B as a function of angle 0 A U a u cos 0 c 1 sin 0 Cos 0 b 0 u cose B d 1 cos 0

Two blocks of mass 10 kg and 5 kg are placed on a rough surface 0 4 as shown in figure Block A is pushed by a horizontal force F 50 N then find normal reaction exerted by the vertical wall on block B F 50 N A 10 kg B 5 kg