619 + Interview Questions in NEWTONS-LAWS-OF-MOTION IN GENERAL AWARENESS Page 6 InterviewSolution

251.	A force `F` is applied on block `A` and `B` and between the blocks `B` and `C` respectively are (Assume frictionless surface) A. `(F)/(7),(2F)/(7)`B. `(6F)/(7),(4F)/(7)`C. `F,(F)/(7)`D. `(4F)/(7),(6F)/(7)`
Answer» Correct Answer - B `a=(F)/(m+2m+4m)=(F)/(7m)` Let normal force between `A` and `B` is `N_(1)` , Then `N_(1)=(2m+4m)a=(6f)/(7)` and between `B` and `C` is `N_(2)` , then `N_(2)=4ma=(4F)/(7)` .

Discussion

252.	Action and reaction can never balance out becauseA. they are equal but not opposite alwaysB. they are unequal in magnitude even though opposite in directionC. though they are equal in magnitude and opposite in direaction they act on different bodiesD. they are unequal in magnitudes
Answer» Correct Answer - C

Discussion

253.	A block of mass 3kg is placed on a rough horizontal surface `(mu_(s)=0.4)` . A forc eof `8.7N` is applied on th eblock. The force of friction between the block and floor is .A. `8.7N`B. 12NC. 10ND. zero
Answer» Correct Answer - A `f_(ms)=mu_(s)mg=0.4xx3xx10N=12N` Since the applied force is less than `12N` therefore the force of friction is equal to the applied force. `f=8.7N` .

Discussion

254.	Assertion: Mass is a property of one object alone, whereas weight results from the interaction of two objects. Reason: The weight of an object is proportional to its mass.A. If both assertion `&` Reason are True `&` the Reason is a corrrect explanation of the Asserion.B. If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.C. If Assertion is Trie but the Reason is False.D. If both Assertion `&` Reason are false
Answer» Correct Answer - B Reason do not explain difference between mass and weight.

Discussion

255.	A person used force `(F)` , shown in figure to move a load with constant velocity on given surface. Identify the correct surface profile: A. B. C. D.
Answer» Correct Answer - A The correct surface profile will be (a), because slope of surface should change from one constant value (non-zero) in terms of sign because force is constant piecewise.

Discussion

256.	A bird is sitting on the floor of a wire cage and the cage is in the hand of a boy . The bird starts flying in the cage . Will the boy experience any change in the weight of the cage ?A. UnchangedB. ReducedC. IncreasedD. Nothing can be said
Answer» Correct Answer - A Unchanged

Discussion

257.	Weight is defined as:-A. Force of attraction by the earthB. Mass of a bodyC. Nature of the bodyD. None of these
Answer» Correct Answer - A Weight is gravitational force.

Discussion

258.	A person used force `(F)` , shown in figure to move a load with constant velocity on given surface. Identify the correct surface profile: A. B. C. D.
Answer» Correct Answer - A during up the incline and down the incline constant forces respectively would be used.

Discussion

259.	A frame will be inertial, if it moves with respect to another inertial frame with a constant :-A. Linear velocityB. Angular velocityC. Linear accelerationD. All of the above
Answer» Correct Answer - A

Discussion

260.	For ordinary terrestrial experimants, the observer is an inertial frame in the following cases isA. A child revolving in a giant wheelB. A driver in a sports car moving with a constant high speed of 200 km/h on a straight road.C. The pilot of an aeroplane which is taking offD. A cyclist negotiating a sharp curve.
Answer» Correct Answer - B

Discussion

261.	In the figure, a block of weight `60N` is placed on a rough surface. The coefficient of friction between the block and the surface is `0.5` . What should be the weight `W` such that the block does not slip on the surface? A. `60N`B. `(60)/(sqrt(2)N`C. `30N`D. `(30)/(sqrt(2)N`
Answer» Correct Answer - C Frictional force: `F=muR=0.5xxm=0.5xx60=30N` Now `F=T_(1)=T_(2)cos45^(@)` or `30=T_(2)cos45^(@)` and `W=T_(2)sin45^(@)` Solving them we get `W=30N`

Discussion

262.	A cork and a metal bob are connected by a string as shown in the figure. If the beaker is given an acceleration towards left then the cork will be thrown towords:- A. RightB. LeftC. upwards with a uniform acceleration of `ms^(-2)`. What would be the readings on the scale in each case?D. Downward
Answer» Correct Answer - B as density of cork is less than of water Pressure force `gt` Pseudo force `therefore` cork moves towards left

Discussion

263.	Action and reaction forces act onA. The same bodyB. The different bodiesC. The horizontal surfaceD. Nothing can be said
Answer» Correct Answer - B

Discussion

264.	A bird weighs 2 kg and is inside a closed cage of 1 kg. If it starts flying, then what is the weight of the bird and cage assemblyA. `1.5` kgB. `2.5` kgC. 3 kgD. 4 kg
Answer» Correct Answer - C

Discussion

265.	A bullet is fired from a gun. The force on the bullet is given by `F=600-2xx10^(5)` t, where F is in newtons and t in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?A. 9NsB. zeroC. `0.9Ns`D. `1.8Ns`
Answer» Correct Answer - C `F=600-2xx10^(5)t=0` implies `t=3xx10^(-3)sec` impulse `I=int_(0)^(1)Fdt=int_(0)^(3xx10^(-3))(600-2xx10^(3)t)dt` `=[600t-10^(5)t^(2)]_(0)^(3xx10^(-3))=0.9Nxxsec`

Discussion

266.	Two block of masses `m_(1)` and `m_(2)` are connected as shown in the figure. The acceleration of the block `m_(2)` is: A. `(m_(2)g)/(m_(1)+m_(2))`B. `(m_(1)g)/(m_(1)+m_(2))`C. `(4m_(2)g-m_(1)g)/(m_(1)+m_(2))`D. `(m_(2)g)/(m_(1)+4m_(2))`
Answer» Correct Answer - A Let `a=acc^(n)` of `m_(1)` , `acc^(n)` of pulley `=(a+0)/(2)=(a)/(2)` If acceleration of `m_(2)=b` Then `0+(b)/(2)=(a)/(2)` Hence `a=b` `T=m_(1)` `a` , `m_(2)g-T=m_(2)a` :. `a(m_(2)g)/(m_(1)+m_(2))` .

Discussion

267.	A ship of mass `3xx10^(2)kg` initially at rest is pulled by a force of `5xx10^(4)` N through a distance of 3m. Neglecting frcition, the speed of the ship at this moment is:A. 3.0m//s`B. `1.5m//s`C. `0.1m//s`D. `2m//s`
Answer» Correct Answer - C `5xx10^(4)xx3=(1)/(2)xx3xx10^(7)xxV^(2)` `10xx10^(-3)=v^(2)` `V=0.1 m//s`

Discussion

268.	In the figure shown neglecting friction and mass of pulley, what is the acceleration of mass `B` ? A. `g//3`B. `5g//2`C. `2g//3`D. `2g//5`
Answer» Correct Answer - D

Discussion

269.	In the figure, at the free end of the light string, a force F is spplied to keep the suspended mass of 18 kg at rest. Then the force exerted by the cirling on the system (assume that the string segments are vertical and the pulleys are light and smooth) is:(`g=10(m)/(s^2)`)A. 200 NB. 120 NC. 180 ND. 240 N
Answer» Correct Answer - D

Discussion

270.	A wagon weighing 1000 kg is moving with a velocity 50 `km//h` on smooth horizontal rails. A mass of 250 kg is dropped into it. The velocity with which it moves now isA. `2.5`km/hourB. 20 km/hourC. 40 km/hourD. 50 km/hour
Answer» Correct Answer - C

Discussion

271.	Identify the relationship which governs the velocities of the four cylinders. Assume all velocities as positive downward .A. `3v_(A) +6v_(B) + 4v_(C) +v_(D) =0`B. `4v_(A) +8v_(B)+4v_(C) +v_(D)=0`C. `3v_(A) +6v_(B) +2v_(C) +v_(D) =0`D. `3v_(A) +10v_(B) +2v_(C) +v_(D) =0`
Answer» Correct Answer - B Let `T` be the tension `TV_(D)+4TV_(C)+8TV_(B)+4TV_(A)=0` `V_(D) +4V_(C) + 8V_(B) + 4V_(A) =0` .

Discussion

272.	With what minimum acceleration mass M must be moved on frictionless surface so that m remains stick to it as shown in figure-2.171. The co-efficient of friction between M & m is `mu` : A. `mug`B. `(g)/(mu)`C. `(mumg)/(M+m)`D. `(mumg)/(M)`
Answer» Correct Answer - B

Discussion

273.	The ring shown in fig. is given a constant horizontal acceleration `(a_(0)=gsqrt(3))`. The maximum deflection of the string from the vertical is `theta_(0)`. Then A. `theta_(0)=30^(@)`B. `theta_(0)=60^(@)`C. at maximum deflection, tension in string is equal to mgD. at maximum deflection, tension in string is equal to `(2mg)/sqrt(3)`
Answer» Correct Answer - A::D

Discussion

274.	A steel wire can withstand a load up to `2940N`. A load of `150 kg` is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passs through the position of equilibrium, isA. `30^(@)`B. `60^(@)`C. `80^(@)`D. `85^(@)`
Answer» Correct Answer - B In equilibrium, `T cos theta = mg`

Discussion

275.	Assertion: When a force `vecF` attempts to slide a body along a surface, a frictional force parallel to the surface and directed so as to oppose the sliding, is exerted on the body by the surface. Reason: It is due to the bonding between the body and the surface.A. If both assertion `&` Reason are True `&` the Reason is a corrrect explanation of the Asserion.B. If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.C. If Assertion is Trie but the Reason is False.D. If both Assertion `&` Reason are false
Answer» Correct Answer - A Bond tension opposes relative motion.

Discussion

276.	Assertion: A body of weight 10N (W) is at rest on an inclined plane `(mu=sqrt(3)/(2))` making an angle of `30^(@)` with the horizontal. The force of friction acting on it is 5N Reason: In above situation, the limiting force of friction is given by `f_("limitting")=mu W cos theta=7.5N`.A. If both assertion `&` Reason are True `&` the Reason is a corrrect explanation of the Asserion.B. If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.C. If Assertion is Trie but the Reason is False.D. If both Assertion `&` Reason are false
Answer» Correct Answer - B `f=mg sin theta=10xx(1)/(2)=5N` `f_("max")=mu mg cos theta=7.5N` NO explanation for friction `lt f` (limmiting)

Discussion

277.	The weight of an aeroplane flying in the air is balanced byA. Vertical component of the thrust created by air currents striking the lower surface of the wingsB. Force due to reaction of gases ejected by the revolving propellerC. Upthrust of the air which will be equal to the weight of the air having the same volume as the planeD. Force due to the pressure difference between the upper and lower surfaces of the wings created by different air speeds on the surfaces
Answer» Correct Answer - D

Discussion

278.	If the Earth be at one fourth its present distance from the sun, how many days will be charged in present one year on the surface of earth?A. `1.5xx10^(8)ms^(-1)`B. `2.1xx10^(8)ms^(-1)`C. `2.6xx10^(8)ms^(-1)`D. `5.2xx10^(8)ms^(-1)`
Answer» Correct Answer - C

Discussion

279.	A railway engine of mass 50 tons is pulling a wagon of mass 40 tons with a force of `4500N`. The resistance force acting is `1N` per ton The tension in the coupling between the engine and the wagon is .A. `1600N`B. `2000N`C. `200N`D. `1500 N`
Answer» Correct Answer - B `F =ma, a =(F_("net"))/(m_(1)+m_(2))` For engine `F -f -T =m_(1)a` .

Discussion

280.	A rod is kept inclined at an angle `theta` with the horizontal A sleeve of mass m can slide on the rod. If the coefficient of friction between the rod and the sleeve is `mu`, for what values of horizontal acceleration a of the rod, towards left, the sleeve will not slide over the rod?
Answer» Correct Answer - `g = (g("sin"theta - mu "cos"theta))/(("cos"theta + mu"sin"theta)) le a le (g("sin"theta + mu"cos"theta))/(("cos"theta - mu"sin"theta))`

Discussion

281.	Two block of masses `M_(1) and M_(2)` are connected with a string passing over a pulley as shown in figure The block `M_(1)` lies on a horizontal surface friction between the block `M_(1)` and the horizontal surface is `mu` The system accelerates. What additional mass `m` should be plased on the block `M_(1)` so that the system does not accelerate ? A. `(M_(2)-M_(1))/(mu)`B. `M_(2)/(mu)-M_(1)`C. `M_(2)-M_(1)/(mu)`D. `(M_(2)-M_(1))mu`
Answer» Correct Answer - B For the equilibrium of block of mass `M_(1)` : Frictional force, `f` =tension in the string, `T` where `T=fmu(m+M_(1))g=m_(3)g` `T=M_(2)g` From (i) and (ii) `mu(m+M_(1))g=M_(3)g` `m=(M_(2))/(mu)-M_(1)` .

Discussion

282.	The force `F` acting on a partical of mass `m` is indicated by the force-time graph shown below. The change in momentum of the particle over time interval from zero to 8 `s` is. A. `24Ns`B. `20Ns`C. `12Ns`D. `6Ns`
Answer» Correct Answer - C `F=(dp)/(dt)` implies `dp=F.dt` or `int_(pi)^(pf)dp=intF.dt` Change in momentum=Area under the `F` versus `t` graph in that in interval `=((1)/(2)xx2xx6)-(2xx3)+(4xx3)` `=6-6+12Ns`

Discussion

283.	The rear side of a truck is open A box of `40kg` mass is placed `5m` away from the open end as shown in The coefficient of friction between the box and the surface is 0.15. On a straight road, the truck starts from rest and accel erating with `2m//s^(2)`. At what dis tance from the starting point does the box dis-tance from the starting point does the box fall from the truck? (Ignore the size of the box) .A. `20m`B. `10m`C. `sqrt20m`D. `5m`
Answer» Correct Answer - A `s =(1)/(2) at^(2) ,a^(1) =a - mu, t =sqrt((2l)/(a^(1))`

Discussion

284.	Two mass A and B of 5 kg and 6 kg are connected by a string passing over a frictionless pulley fixed at the corner of table as shown in figure-2.179. The coefficient of friction between A and the table is 0.3. The minimum mass of C that must be placed on A to prevent it from moving is equal to : (Take `g=10ms^(2)`) A. 15 kgB. 10 kgC. 5 kgD. 3 kg
Answer» Correct Answer - A

Discussion

285.	A chain is lying on a smooth table with half its length hanging over the edge of the table [fig(i)]. If the chain is released it slips off the table in time t1. Now, two identical small balls are attached to the two ends of the chain and the system is released [fig(ii)]. This time the chain took `t_(2)` time to slip off the table. Which time is larger, `t_(1)` or `t_(2)`?
Answer» Correct Answer - `t_(2)`

Discussion

286.	A force `F_1` acts on a particle so as to accelerate it from rest to a velocity v. The force `F_1` is then replaced by `F_2` which decelerates it to restA. `F_(1)` most be equal to `F_(2)`B. `F_(1)` may be equal to `F_(2)`C. `F_(1)` must be unequal to `F_(2)`D. None of these
Answer» Correct Answer - B `v^(2)=0+(F_(1))/(m)s_(1)` `0=v^(2)-(F_(2))/(m)s_(2)` `F_(1)s_(1)=F_(2)s_(2)`

Discussion

287.	An empty plastic box of mass 9 kg is found to accelerate up at the rate of `g//3` when placed deep inside water. Mass of the sand that should be put inside the box so that it may accelerate down at the rate of `g//4` is :A. 7 kgB. 6 kgC. 9 kgD. None of these
Answer» Correct Answer - A

Discussion

288.	Brakes are applied to car moving with disengaged engine, bringing it to a halt after `2s` Its velocity at the momnet when the breaks are applied if the coefficient of friction between the road and the tyres is `0.4` is .A. `3.92 ms^(-1)`B. `7.84 ms^(-1)`C. `11.2 ms^(-1)`D. `19.6 ms^(-1)`
Answer» Correct Answer - B `v = u + at, a = mug`

Discussion

289.	A boy having a mass equal to 40 kilograms is standing in an elevator. The force felt by the feet of the boy will be greatest when the elevator `(g=9.8"metres"//sec^(2))`A. Stands stillB. Moves downward at a constant velocity of 4 metres/secC. Accelerates downward with an acceleration equal to `4"metres"//sec^(2)`D. Accelerates upward with an acceleration equal to `4"metres"//sec^(2)`
Answer» Correct Answer - D

Discussion

290.	A horizontal circular turning has a curved length L and radius R. A car enters the turn with a speed `V_(0)` and its speed increases at a constant rate f. If the coefficient of friction is `mu`, (a) At what time `t_(0)`, after entering the curve, will the car skid? (Take it for granted that it skids somewhere on the turning) (b) At a time `t (lt t_(0))` what is the force of friction acting on the car?
Answer» Correct Answer - (a) `t_(0) = ([R^(2)(mu^(2) g^(2)- f^(2))]^((1)/(4))- V_(0))/(f)` (b) `msqrt(((V_(0) + ft)^(4))/(R^(2)) + f^(2))`

Discussion

291.	The limiting friction between two surface does not dependA. on the nature of two surfaceB. on normal reactionC. on the weight of the bodyD. on volume of the body
Answer» Correct Answer - D

Discussion

292.	Assertion : Angle of repose is equal to angle of limiting friction.Reason : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.A. If both assertion `&` Reason are True `&` the Reason is a corrrect explanation of the Asserion.B. If both Assertion `&` Reason are True but Reason is not correct explanation of the Assertion.C. If Assertion is Trie but the Reason is False.D. If both Assertion `&` Reason are false
Answer» Correct Answer - B Angle of repose `=tan^(-1)(mi)=` angle of limmiting friction. For just motion friction is limiting.

Discussion

293.	Two masses `M_(1)` and `M_(2)` connected by means of a string which is made to pass over light, smooth pulley are in equilibrium on a fixed smooth wedge as shown in figure. If `theta =60^(@)` and `alpha =30^(@)` then the ratio of `M_(1)` to `M_(2)` is .A. `1:2`B. `2:sqrt3`C. `1:sqrt3`D. `sqrt3:1`
Answer» Correct Answer - C `m_(1)g sin theta = m_(2) g sin alpha`

Discussion

294.	A body of mass `m` is placed over a smooth inclined plane of inclination theta. Which iis placed over a lift which is moving up with an acceleration `a_(0)` . Base length o f the inclined plane is `L` . Calculate the velocity of the block with respect to lift at the bottom, if it is allowed to slide down from the top o fthe plane from rest.A. `sqrt(2(a_(0)+g)Lsintheta)`B. `sqrt(2(a_(0)+g)Lcostheta)`C. `sqrt(2(a_(0)+g)Ltantheta)`D. `sqrt(2(a_(0)+g)Lcottheta)`
Answer» Correct Answer - C Acceleration along the plane with respect to lift is, `a=(a_(0)+g)sintheta` Initial velocity=0 `v^(2)=u^(2)+2as` `v=sqrt(2(a_(0)+g)sintheta(l)/(costheta))` .

Discussion

295.	A sphere of mass M is held at rest on a horizontal floor. One end of a light string is fixed at a point that is vertically above the centre of the sphere. The other end of the string is connected to a small particle of mass m that rests on the sphere. The string makes an angle `alpha = 30^(@)` with the vertical. Find the acceleration of the sphere immediately after it is released. There is no friction anywhere.
Answer» Correct Answer - `(sqrt(3)mg)/(3m + 4M)`

Discussion

296.	A heavy body of mass `25kg` is to be dragged along a horizontal plane (`mu` = `(1)/(sqrt(3))`. The least force required is `(1 kgf = 9.8 N)`A. 25kgfB. 2.5kgfC. 12.5kgfD. 50kgf
Answer» Correct Answer - C

Discussion

297.	A stone of mass m tied to a string of length l is rotated in a circle with the other end of the string as the centre. The speed of the stone is v. If the string breaks, the stone will moveA. towards the centreB. away from the centreC. along a tangentD. will stop
Answer» Correct Answer - C When string breack, only tangential component of acceleration will survive. Hence, path following is tangential to circular path.

Discussion

298.	A small sized mass `m` is attached by a massless string (of length `L`) to the top of a fixed frictionless solid cone whose axis is vertical. The half angle at the vertex of cone is theta. If the mass `m` moves around in a horizontal circle at speed `v` , what is the maximum value of `v` for which mass stay in contact with the comes? (g is acceleration due to gravity.) A. `sqrt(gLcostheta)`B. `sqrt(gLsintheta)`C. `sqrt(gLsinthetatantheta)`D. `sqrt(gl tantheta)`
Answer» Correct Answer - C At maximum velocity the mass will just loose contact with cone and will behave like free conical pendulum with time period `T=2pisqrt((Lcostheta)/(g))` implies `omega=(2pi)/(T)sqrt((g)(Lcostheta))` Hence `v_(max)=(Lsintheta)omega=sqrt(gLsinthetatantheta)`

Discussion

299.	In the last question, the axis of the disc is tilted slightly to make an angle`theta` with the vertical. Redo the problem for this condition and check the result by putting `theta = 0` in your answer.
Answer» Correct Answer - `omega = sqrt((g)/(R)("cos"theta - 2 "sin"theta))`

Discussion

300.	A stone of mass 1kg tied to a light inextensible sstring of length `L=10m` is whirling in a circular path of radius `L` in vertical plane. If the ratio of the maximum tension in the string to the minimmum tension in the string is 4 and if `g` is taken to be `10ms^(-2)` , the speed of the stone at the highest point of the circle is.A. `10ms^(-1)`B. `5sqrt(2)ms^(-1)`C. `10sqrt(3)`D. None of these
Answer» Correct Answer - C `(T_(max))/(T_(mim.))=((Mv_(l)^(2)+mg)/(L)+mg)/(mv_(H)^(2)/(L)-mg)=4` or `(v_(L)^(2))/(L)+g=(4v_(H)^(2))(L)-4g` or `(v_(L)^(2)+2g(2L))/(L)=(v_(H)^(2))/(L)-5g` or `(v_(H)^(2))/(L)+9g=(4v_(L)^(2))/(L)` or `(3v_(H)^(2))/(L)=9g` or `v_(H)=sqrt(3gl)` `=sqrt(3xx10xx10)=10sqrt(3)m//s`

Discussion

Explore topic-wise InterviewSolutions in .

A force `F` is applied on block `A` and `B` and between the blocks `B` and `C` respectively are (Assume frictionless surface) A. `(F)/(7),(2F)/(7)`B. `(6F)/(7),(4F)/(7)`C. `F,(F)/(7)`D. `(4F)/(7),(6F)/(7)`

Action and reaction can never balance out becauseA. they are equal but not opposite alwaysB. they are unequal in magnitude even though opposite in directionC. though they are equal in magnitude and opposite in direaction they act on different bodiesD. they are unequal in magnitudes

A block of mass 3kg is placed on a rough horizontal surface `(mu_(s)=0.4)` . A forc eof `8.7N` is applied on th eblock. The force of friction between the block and floor is .A. `8.7N`B. 12NC. 10ND. zero

A person used force `(F)` , shown in figure to move a load with constant velocity on given surface. Identify the correct surface profile: A. B. C. D.

A bird is sitting on the floor of a wire cage and the cage is in the hand of a boy . The bird starts flying in the cage . Will the boy experience any change in the weight of the cage ?A. UnchangedB. ReducedC. IncreasedD. Nothing can be said

Weight is defined as:-A. Force of attraction by the earthB. Mass of a bodyC. Nature of the bodyD. None of these

A person used force `(F)` , shown in figure to move a load with constant velocity on given surface. Identify the correct surface profile: A. B. C. D.

A frame will be inertial, if it moves with respect to another inertial frame with a constant :-A. Linear velocityB. Angular velocityC. Linear accelerationD. All of the above

In the figure, a block of weight `60N` is placed on a rough surface. The coefficient of friction between the block and the surface is `0.5` . What should be the weight `W` such that the block does not slip on the surface? A. `60N`B. `(60)/(sqrt(2)N`C. `30N`D. `(30)/(sqrt(2)N`

A cork and a metal bob are connected by a string as shown in the figure. If the beaker is given an acceleration towards left then the cork will be thrown towords:- A. RightB. LeftC. upwards with a uniform acceleration of `ms^(-2)`. What would be the readings on the scale in each case?D. Downward

Action and reaction forces act onA. The same bodyB. The different bodiesC. The horizontal surfaceD. Nothing can be said

A bird weighs 2 kg and is inside a closed cage of 1 kg. If it starts flying, then what is the weight of the bird and cage assemblyA. `1.5` kgB. `2.5` kgC. 3 kgD. 4 kg

A bullet is fired from a gun. The force on the bullet is given by `F=600-2xx10^(5)` t, where F is in newtons and t in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?A. 9NsB. zeroC. `0.9Ns`D. `1.8Ns`

Two block of masses `m_(1)` and `m_(2)` are connected as shown in the figure. The acceleration of the block `m_(2)` is: A. `(m_(2)g)/(m_(1)+m_(2))`B. `(m_(1)g)/(m_(1)+m_(2))`C. `(4m_(2)g-m_(1)g)/(m_(1)+m_(2))`D. `(m_(2)g)/(m_(1)+4m_(2))`

A ship of mass `3xx10^(2)kg` initially at rest is pulled by a force of `5xx10^(4)` N through a distance of 3m. Neglecting frcition, the speed of the ship at this moment is:A. 3.0m//s`B. `1.5m//s`C. `0.1m//s`D. `2m//s`

In the figure shown neglecting friction and mass of pulley, what is the acceleration of mass `B` ? A. `g//3`B. `5g//2`C. `2g//3`D. `2g//5`

A wagon weighing 1000 kg is moving with a velocity 50 `km//h` on smooth horizontal rails. A mass of 250 kg is dropped into it. The velocity with which it moves now isA. `2.5`km/hourB. 20 km/hourC. 40 km/hourD. 50 km/hour

Identify the relationship which governs the velocities of the four cylinders. Assume all velocities as positive downward .A. `3v_(A) +6v_(B) + 4v_(C) +v_(D) =0`B. `4v_(A) +8v_(B)+4v_(C) +v_(D)=0`C. `3v_(A) +6v_(B) +2v_(C) +v_(D) =0`D. `3v_(A) +10v_(B) +2v_(C) +v_(D) =0`

With what minimum acceleration mass M must be moved on frictionless surface so that m remains stick to it as shown in figure-2.171. The co-efficient of friction between M & m is `mu` : A. `mug`B. `(g)/(mu)`C. `(mumg)/(M+m)`D. `(mumg)/(M)`

If the Earth be at one fourth its present distance from the sun, how many days will be charged in present one year on the surface of earth?A. `1.5xx10^(8)ms^(-1)`B. `2.1xx10^(8)ms^(-1)`C. `2.6xx10^(8)ms^(-1)`D. `5.2xx10^(8)ms^(-1)`

A railway engine of mass 50 tons is pulling a wagon of mass 40 tons with a force of `4500N`. The resistance force acting is `1N` per ton The tension in the coupling between the engine and the wagon is .A. `1600N`B. `2000N`C. `200N`D. `1500 N`

A rod is kept inclined at an angle `theta` with the horizontal A sleeve of mass m can slide on the rod. If the coefficient of friction between the rod and the sleeve is `mu`, for what values of horizontal acceleration a of the rod, towards left, the sleeve will not slide over the rod?

The force `F` acting on a partical of mass `m` is indicated by the force-time graph shown below. The change in momentum of the particle over time interval from zero to 8 `s` is. A. `24Ns`B. `20Ns`C. `12Ns`D. `6Ns`

A force `F_1` acts on a particle so as to accelerate it from rest to a velocity v. The force `F_1` is then replaced by `F_2` which decelerates it to restA. `F_(1)` most be equal to `F_(2)`B. `F_(1)` may be equal to `F_(2)`C. `F_(1)` must be unequal to `F_(2)`D. None of these

An empty plastic box of mass 9 kg is found to accelerate up at the rate of `g//3` when placed deep inside water. Mass of the sand that should be put inside the box so that it may accelerate down at the rate of `g//4` is :A. 7 kgB. 6 kgC. 9 kgD. None of these

Brakes are applied to car moving with disengaged engine, bringing it to a halt after `2s` Its velocity at the momnet when the breaks are applied if the coefficient of friction between the road and the tyres is `0.4` is .A. `3.92 ms^(-1)`B. `7.84 ms^(-1)`C. `11.2 ms^(-1)`D. `19.6 ms^(-1)`

The limiting friction between two surface does not dependA. on the nature of two surfaceB. on normal reactionC. on the weight of the bodyD. on volume of the body

Two masses `M_(1)` and `M_(2)` connected by means of a string which is made to pass over light, smooth pulley are in equilibrium on a fixed smooth wedge as shown in figure. If `theta =60^(@)` and `alpha =30^(@)` then the ratio of `M_(1)` to `M_(2)` is .A. `1:2`B. `2:sqrt3`C. `1:sqrt3`D. `sqrt3:1`

A heavy body of mass `25kg` is to be dragged along a horizontal plane (`mu` = `(1)/(sqrt(3))`. The least force required is `(1 kgf = 9.8 N)`A. 25kgfB. 2.5kgfC. 12.5kgfD. 50kgf

A stone of mass m tied to a string of length l is rotated in a circle with the other end of the string as the centre. The speed of the stone is v. If the string breaks, the stone will moveA. towards the centreB. away from the centreC. along a tangentD. will stop

In the last question, the axis of the disc is tilted slightly to make an angle`theta` with the vertical. Redo the problem for this condition and check the result by putting `theta = 0` in your answer.