40048 + Interview Questions in Physics in Class 11 Page 265 InterviewSolution

13201.	A block of mass 2kg is attached with a spring of spring constant 4000Nm^-1 and the system is kept on smooth horizontal table. The other end of the spring is attached with a wall. Initially spring is stretched by 5cm from its natural position and the block is at rest. Now suddenly an impulse of 4kg-ms^-1 is given to the block towards the wall. Approximate distance travelled by the block when it comes to rest for a second time (not including the initial one) will be (Take sqrt(45)=6.70) Displacement of the rod by the time the insect meet the moth is
Answer» (a) `L/2` (B) `L` (c) `(3L)/(4)` (d) zero Solution :`p_i=p_f` `:. 0=(8m)(2v)-(16m)(v)+(48m)v^'` Here `v^'=` ABSOLUTE speed of rod `=0` `:.` Displacement of rod=0`

Discussion

13202.	Proveimpulse momentum equation
Answer» Solution :If aforce `(F )` actson a bodyin a veryshortintervalof time `(Detla t)`then formNewton'ssecondlaw inmagnitudeforms Intergratingover timeforman intialtime`t_(i)` toa finaltime `t_(f)` we get overset(i)UNDERSET(f ) (int) dp=overset(i)underset(f ) (int) Fdtg` `P_(i)- P_(i)= underset(t) overset(t)(int)F dt` `p_(1)=`initialmomentum of the bodyat time `t_(i)` `p_(f)=` finalmomentum of the bodyat time `f_(f)` `p_(f)- p_(i) = Delta p`changein MOMENTUM of thebodyduringthe TIMEINTERVAL Theintegral`underset(t ) overset( t ) (int)F dt = J` iscalledthe impulseand itis equalto change a in momentum of the body . If theforce is constantover the timeintervalthen `underset(t ) overset(t ) (int ) Fdt= Funderset( t) overset( t) dt = F (t_(1) - t_(1)) = F Delta t` `F Delta t= Delta p` Impulse = Changein momentum

Discussion

13203.	If a body of mass m is taken out from a point below the surface of earth equal to half the radius of earth, R, to a height R above the earths surface, then work done on it will be_____mgr
Answer» 5/6 6/7 7/8 8/9 Answer :C

Discussion

13204.	Two particles are projected with same velocity but at angles of projection 35^(@) and 55^(@). Then their horizontal ranges are in the ratio of
Answer» `1:2` `2:1` `1:1` `4:1` ANSWER :C

Discussion

13205.	If the tension in the cable supporting an elevator is equal to the weight of the elevator, the elevator may be (a) gaoing up with increasing speed(b) going down with increasing speed(c ) going up with uniform speed(d) going down with uniform speed
Answer» a, B are TRUE b, C are true c, d are true a, c are true ANSWER :C

Discussion

13206.	A block of wood weighs 12 kg and has a relative density 0.6. It is to be in water with 0.9 of its volume immersed. What weight of a metal is needed (a) if the metal is on the top of wood, (b) if the metal is attached below the wood? [RD of metal =14]
Answer» ANSWER :[(a) 6KG, (B) 6.5 KG]

Discussion

13207.	A small mass m is transferred from the centre of a hollow sphere of mass M to infinity. Find work done in the process. Compare this with the situation if instead of a hollow sphere, a solid sphere of same mass were there.
Answer» Solution :We know at infinity gravitional potential is taken ZERO. Thus if `V_(C )` be the GRAVITATIONAL potential at centre of holow sphere then external work required the procedd is `W = m(0-V_(C ))` or `= m(0-((GM)/(R )))=(GMm)/(R )` Here `V_(C )= -(GM)/(R )`, the potential at the centre of a hollow sphere of mass M and radius R. If a so solid sphere is here, we have at its centre `V_(C )= - (3)/(2)(GM)/(R )` Thus work required will be `W = m[0-(-(3)/(2)(GM)/(R ))]=(3)/(2)(GMm)/(R )` We can SEE in second case more work is required for the process.

Discussion

13208.	Solar constant and Stefan's constant have same dimensions in
Answer» Mass length Time all the above Answer :A

Discussion

13209.	A body is sliding down an inclined plane having coefficient of friction 0.5. If the normal reaction is twice that of the resultant downward force along the inclination the angle between the inclined plane and the horizontal is
Answer» SOLUTION :`45^(@)`

Discussion

13210.	An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork of frequency 256 Hz, if the length of the column in centimeter is (velocity of sound inair 340 m/s)
Answer» `21.25` `125` `62.50` `33.2` Solution :`F = (v)/(4L) IMPLIES L = (v)/(4f) = (34000)/(4 xx 256) = 33.2 ` CM

Discussion

13211.	A moving blockhaving mass m , collides with another stationary block having mass 4m , The lighter block comes to rest after collision . When the intial velocity of the lighter block is v, then the value of coefficient of restitution (e ) will be
Answer» `0.4` `0.5` `0.8` `0.25` Solution :From the law conservation of VELOCITY , ` " P=p" mv =4mv_(2)"" :. V_(2) = (v_(1))/4` ` :. ` Restitutional VALUE , `(e)= (v_(2)-v_(1))/(v_(1)-v_(2))=((v_(1))/4-0)/(v_(1)-0)=1/4 =0.25`.

Discussion

13212.	Earth (uniform solid sphere of Mass M Radius rotaes about its North pole - south pole diameter at a constant angular velocity omega. A small block of mass m kept at a colatitude of theta doesn'tslip on earth's surface Then which of the following statements is INCORRECT ?
Answer» Angular MOMENTUM of the BLOCK about centre of the EARTH is conserved Torque of Gravitational force on the block about the centre of the earth is zero Angular velocity of the block about the centre of the earth is `omega sin theta` Angular momentum of the block about the centre of the earth is `mR^(2)omegasin theta` ANSWER :A

Discussion

13213.	A uniform disc of mass 2kg and radius 1m is mounted on an axle supported on fixed frictionless bearings. A light cord is wrapped around the rim of the disc and mass of 1kg is tied to the free end. If it is released from rest,
Answer» the tention in the cord is 5N in FIRST 4 seconds the angular displacement of the disc is 40 RAD the WORK done by the torque on the disc in first 4 sec. is 200J the increase in the kinetic energy of the disc in the first 4 seconds is 200J Answer :A::B::C::D

Discussion

13214.	Two bodies having the same mass 2kg each have different surface areas 50 m^(2) and 100 m^(2) in contact with a horizontal plane. If the coefficient of friction is 0.2, the forces of friction that come into play when they are in motion will be in the ratio
Answer» `1:1` `1:2` `2:1` `1:4` ANSWER :A

Discussion

13215.	The linear magnification is produced by a telescope having an objective of 50cm and eyepiece of 5cm focal length when used to read a scale 3m away is
Answer» 1.2 2 0.6 4 Answer :A

Discussion

13216.	A car weighing 100 kg is on a slope that makes an angle 30^(@) with the horizontal. The component of car.s weight parallel to the slop is(g = 10ms^(-2))
Answer» 500 N 1000 N 15,000 N 20,000 N Answer :A

Discussion

13217.	A satellite A of mass m is at a distance of r from the surface of the earth. Another satellite B of mass 2m is at a distance of 2r from the earth's centre. Their time periods are in the ratio of
Answer» `1:2` `1:16` `1:32` `1:2sqrt2` ANSWER :D

Discussion

13218.	Wave equation for one progressive harmonic wave isy = 10 ^(-4) sin (600 t - 2x + (pi)/(3))m and t is in s). Velocity of the wave would be ...... m/s
Answer» 300 600 1200 200 Solution :Comparing GIVEN equation, `y = 10 ^(-4) SIN (600 t - 2x + (pi)/(t))` with `y = a sin (omega t - kx +phi)` we get, `omega = 600 rad//s` `K = 2 rad //m` `therefore v = (omega )/(k) = (600)/(2) = 300 (m)/(s)`

Discussion

13219.	Two rings of the same radius and mass are placed such that their centres are at a common point and their planes are perpendicular to each other. The moment of inertia of the system about an axis passing through the centre and perpendicular to the plane of one of the rings is (mass of the ring = m, radius = r)
Answer» `(1)/(2) MR^(2)` `mr^(2)` `(3)/(2) mr^2` `2mr^2` Solution :Because the planes of TWO rings are mutually perpendicular and centres are coincident , hence an axis , which is passing through centre of one of the rings and perpendicular to its PLANE , will be along the diameter of other ring . Hence , moment of INERTIA of the system `I_(CM) + I_("diameter") = mr^(2) + (mr^(2))/(2) = (3)/(2) mr^(2)`

Discussion

13220.	A gas obeys PV^2= constant in addition to PV =RT. If on heating, the temperature is doubled, the volume of the gas is
Answer» V/2 2V `V//SQRT2` `sqrt2 V` ANSWER :A

Discussion

13221.	China wares are wrapped in straw paper before packing. Why?
Answer» Solution :The STRAW paper between the China ware increases the time of EXPERIENCING the JERK during transportation. Hence impact of FORCE reduces on China wares.

Discussion

13222.	Find the dimensions of (i) force (ii) surface tension and (iii) momentum in terms of frequency, velocity and density as fundamental units.
Answer» SOLUTION :Frequency `n=T^(-1),T=1/n` Velocity `v=LT^(-1),L=vT=v/n` Density `d=ML^(-3),M=dL^(3)=(dv^(3))/(n^(3))` (i) Force `=MLT^(-2)=(dv^(3))/(n^(3))xxv/nxxn^(2)=(dv^(4))/(n^(2))` (ii) SURFACE tension `=MT^(-2)=(dv^(3))/(n^(3))xxn^(2)=(dv^(3))/n` (iii) Momentum `=MLT^(-1)=(dv^(3))/(n^(3))xxv/nxxn=(dv^(4))/(n^(3))`

Discussion

13223.	Define unit of a physial quantity.
Answer» Solution :A physical quantity is made of 2 parts that is NUMERICAL VALUE and unit. Unit gives the absolute value of 1 numerical value of that physical quantity.

Discussion

13224.	Consider three blocks of masses m_(1), m_(2), m_(3) interconnected by strings which are pulled by a common force F on a frictionless horizontal table as in the figure. The tension T_(1) and T_(2) are also indicated a) T_(2) gt T_(1)" if "m_(2) gt m_(1) b) T_(2) =T_(1)" if "m_(2)=m_(1) c) T_(2) gt T_(1) always d) "acceleration of the system"=(F)/(m_(1)+m_(2)+m_(3))
Answer» a, b b, d a, d c, d Solution :`F=ma a=(F_("NET"))/(M), T_(1)=m_(1)a, T_(2)=(m_(1)+m_(2))a`

Discussion

13225.	Which is most elastic?
Answer» iron copper quartz wood Answer :C

Discussion

13226.	If the acceleration due to gravity on the moon is one-sixth of that on the earth. What will be the change in length of a second pendulum there so that it may beat a second there ? Take acceleration due to gravity on earth surface =9.8 ms^(-2).
Answer» Solution :On earth `g=9.87 m//s^(2)`. Let L be the LENGTH of second pendulum . Then `T=2s` `T=2pi sqrt((l)/(g))` (or) `l=(T^(2)g)/(4pi^(2))=(2^(2)xx9.8)/(4XX(22//7)^(2))` `=0.9921 m =99.21 CM` On moon, `g_(m)=(1)/(6)g=(9.8)/(6) ms^(-2)` `l'=(T^(2)g_(m))/(4pi^(2))=(2^(2)xx(9.8//6))/(4xx(22//7)^(2))` `=.1654 m=16.54 m` change4 in length `=l-l'=99.21-16.54` `=82.67 cm`

Discussion

13227.	Express Ok on Fahrenheit scale.
Answer» `-459.67^(@)` F `240.6^(@)` F `-320^(@)` F `373^(@)` F ANSWER :A

Discussion

13228.	At highest point acceleration of projectile is zero.
Answer» Answer :FALSE. At HIGHEST POINT acceleration of PROJECTILE is 'g'.

Discussion

13229.	A thermodynamic process of one mole ideal monoatomic gas is shown in figure. The efficiency of cyclic process ABCA will be
Answer» <P>0.25 0.125 0.5 0.077 Solution :`W=(1)/(2)P_(0)V_(0), T_(A)=T_(0),T_(B)=2T_(0),T_(C)=4T_(0)` Heat supplied =`Q_(AB)+Q_(BC)=C_(V)T_(0)+C_(p)2T_(0)` `=(13)/(2)RT_(0)=(13)/(2)P_(0)V_(0)` `therefore` Efficiency of the cyclic process `((1)/(2) P_(0)V_(0))/((13)/(2)P_(0)V_(0))xx100=(1)/(13)xx100=7.7%`

Discussion

13230.	When an air bubble moves up from the bottom of a lake a) velocity decreases and becomes zero b) acceleration increases and becomes zero c) velocity increases and becomes constant d) acceleration decreases and becomes zero
Answer» a, d are correct a, B are correct C, d are correct c is correct Answer :C

Discussion

13231.	A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration a_(c) is varying with time t as a_(c )= k^(2) rt^(2) where k is a constant. What is the power delivered to the particle by the forces acting on it?
Answer» <P> Solution :As `a_(c )= (V^(2)//r) " so" (v^(2)//r)= k^(2) r t^(2)` Kinetic energy `K= (1)/(2) mv^(2)= (1)/(2) mk^(2) r^(2) t^(2)` Now by work -Enetgy THEOREM `W= Delta K= (1)/(2) mk^(2) r^(2) t^(2)- 0 rArr P= (dw)/(dt)` `rArr P= (d)/(dt) = (1)/(2) mk^(2) r^(2) t^(2)= mk^(2) r^(2) t`

Discussion

13232.	If the coefficient of friction of a surface is sqrt 3, then the angle of inctination of the plane to make a body on it just to slide is
Answer» `30^@` `45^@` `60^@` `80^@` Answer :C

Discussion

13233.	A uniform rope of length .L. and linear density .mu. is on a smooth horizontal table with a lentht .l. lying on the table. The work done in pulling the hanging part on to the table is
Answer» `(MUG(L-l)^(2))/(2)` `(mug(L-l)^(2))/(2L^(2))` `(MUL(L-l)^(2))/(2L^(2))` `(mugl)/(2(L-l))` ANSWER :A

Discussion

13234.	In the figure shown, the mass of the trolley is 100 kg and it can move without friction on the horizontal floor. It length is 12 cm. The mass of the girl is 50 kg. Friction exists between is 12 m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley's upper surface, with mu = 1//3, The girl can run with a maximum speed = 9 m//s on the surface of the trolley, with respect to the surface = 9 m//s on the surface of thr trolley, with respect to the surface. At t=0 the girlm starts running from left to the right. The trolley was initially stationary. (g = 10 m//s^(2)) Suppose the girl accelerates slowly, at a constant rate, and acquires the relative speed of 9 m//s only when it reaches the right end of the trolley, then what must be the earth frame acceleration of the girl ?
Answer» `2.5 m//s^(2)` `2.25 m//s^(2)` `1.125 m//s^(2)` `3.375 m//s^(2)` ANSWER :B

Discussion

13235.	A body of mass 3 kg is moving along a straight line with a velocity of 24 ms^(-1). When it is at a point ‘P’ a force of 9 N acts on the body in a direction opposite to its motion. The time after which it will be at 'P' again is,
Answer» 8S 16s 12s 24s Solution :When it reaches the point .P. again S = 0, USING `a=(F)/(m), S=ut+(1)/(2)at^(2)`

Discussion

13236.	In the figure shown, the mass of the trolley is 100 kg and it can move without friction on the horizontal floor. It length is 12 cm. The mass of the girl is 50 kg. Friction exists between is 12 m. The mass of the girl is 50 kg. Friction exists between the shoes of the girl and the trolley's upper surface, with mu = 1//3, The girl can run with a maximum speed = 9 m//s on the surface of the trolley, with respect to the surface = 9 m//s on the surface of thr trolley, with respect to the surface. At t=0 the girlm starts running from left to the right. The trolley was initially stationary. (g = 10 m//s^(2)) At a certain moment when the girl was accelerating, the earth frame accelerating of the trolley is found to be 1m//s^(2). At this moment, the friction force between the girl's shoes and the trolley's surface is :
Answer» 200 N 150 N 100N None of these Answer :C

Discussion

13237.	Four holes of radius R are cut fro a thin square plate of side 4R and mass M. The moment of inertia of the remaining portion about z-axis is ((x)/(3)-(10pi)/(16))"MR"^(2) where 'x' is
Answer» ANSWER :8

Discussion

13238.	About what axis would a uniform cube have its minimum moment of inertia?
Answer» SOLUTION :About an AXIS joining the opposite comers and PASSING through the centre of the CUBE.

Discussion

13239.	A constant force is applied on a 10kg mass at rest. The ratio of works done is 1st, 2nd and 3rd seconds is
Answer» `1 : 2: 3` `1 : 3 : 5` `1 : 4 : 9` `1 : 1 : 1` Answer :B

Discussion

13240.	A block of ice starts slilding down from the top of an inclined roof of a house along a line of the greatest slope. The inclination of the roof with the horizontal is 30^(@). The height of the highest and lowest points of the roof are 8.1 m and 5.6 m respectivley. At what horizontal distance from the lowest point will the block hit the ground? Neglect air friction [g=9.8m//s^(2)]
Answer» Solution :Acceleration of the block along the greatest slope in equal to `a=g sin 30^(@)` Distance TRAVELLED by the block along the greatest slope is equal to `S=((8.1-5.6))/(sin 30^(@))=5m` If u be the speed of the block when it is just abou to LEAVE the roof then `u^(2)=0+2gsin 30^(@)xx5impliesu=7m//s` If t be the TIME taken on hit the ground then `5.6=u sin 30^(@)t+1/2"gt"^(2)=7/2t+1/2xx9.8t^(2)` `implies7t^(2)+5t-8=0` `t=(-5+-sqrt(25-(4)(7)xx(-8)))/(2xx7)` `impliest=(-5+-15.78)/14s`, -ve value is to be rejected , i.e. `t=(-5+15.78)/14=0.77` SEC Horizontal distance travelled is equal to `x=u cos 30^(@)t=(7sqrt(3))/2xx10.78/14mimpliesx=4.67m`

Discussion

13241.	A particle moves in x-y plane according to the law x = 4 sin 6t and y=4(1-cos6t). The distance traversed by the particle in 4 seconds is (x and y are in meters)
Answer» 96 m 48 m 24 m 108 m Answer :A

Discussion

13242.	A uniform solid cylindrical roller of mass 'm' is being pulled on a horizontal surface with force F parallel to the surface and applied at its centre. If the acceleration of the sylinder is 'a and it is rolling without slipping then the value of 'F' is :
Answer» 2MA `3/2` ma ma `5/3` ma Answer :B

Discussion

13243.	Equal torques are applied on acylinder and a sphere. Both have same mass and radius rotates about its axis and sphere rotates about one of its diameter. Which will rotates acquire greater speed and why?
Answer» SOLUTION :`TAU=I , alpha, alpha=(tau)/(I)` `alpha` in cylinder, `alpha_(C)=(tau)/(I_(C))` `alpha` in sphere, `alpha_(s)=(tau)/(I_(S))` `(alpha_(C))/(alpha_(S))=(I_(S))/(I_(C))=((2)/(5)MR^(2))/(MR^(2))=(2)/(3)`

Discussion

13244.	Consider the situation shown in figure. Initially the spring is unstretched when the system is released from rest. Assuming no friction in the pulley, find the maximum elongation of the spring?
Answer» `(MG)/k` `(2mg)/k` `(mg)/(2K)` `(2mg)/(3k)` Answer :B

Discussion

13245.	If the momentum of a body decreas by 30% its kinetic energy decreases by
Answer» 0.6 0.51 0.69 0.9 Answer :B

Discussion

13246.	For the wave discribed in Exercise 15.8, plot the displacement (y) versus (t) graphs for x=0, 2 and 4 cm. What are the shapes of these graphs ? In which aspects does the oscillatory motion in travelling wave differ from one point to another: amplitude, frequency or phase ?
Answer» Solution :Given wave EQUATION is `y = 3 sin (36 t +0.018 x + (pi)/(4)) cm ""…(1)` `implies` Phase of a particle at distance x from origin of wave at time t is `theta = 36 t + 0.018x + (pi)/(4) rad ""…(2)` Now we are given three particles whose displacement are to be found out at different instnats of time. They are LOCATED at `x=0,` x=2 cm and x=4 cm respectively. Let us consider their simple harmonic oscillations one by one. For particle at `x=0,` from equation (1), `y =3 sin (36 t + (pi)/(4)) ""...(3)` `therefore y= a sin ((2pi )/(T) t + (pi)/(4))` (Where `(2pi)/(T) = omega = 36 (rad)/(s)) ...(4)` From above equation we can find out vaues of DISPLACEMENTS y at `t =0, (T)/(8), (2T)/(8), (3T)/(8), (4T)/(8),...,` `(8T)/(8) = T` as flollows. `(1) At t =0, y = a sin "" (pi)/(4) = (a)/(sqrt2)` (2)` At t = (T)/(8), y = a sin ((2pi)/(T) xx (T)/(8) + (pi )/(4))` `=a sin ((pi)/(2)) =a` `(3) At t = (2T)/(8), y =a sin ((2pi)/(T) xx (2T)/(8) + (pi)/(4))` `=a sin ((pi)/(2) +(pi)/(4)) =a cos ""(pi)/(4) = (a)/(sqrt2)` `(4) At t= (3T)/(8), y= a sin ((2pi)/(T) xx (3T)/(8) + (pi)/(4))` `=a sin (pi) =0` `(5) At t = (4T)/(8), y = a sin ((2pi)/(T) xx (4T)/(8) + (pi)/(4))` `= a sin (pi + (pi)/(4)) =a (-sin "" (pi)/(4)) =- (a)/(sqrt2)` `(6)At t = (5t)/(8), y = a sin ((2pi)/(T) xx (5T)/(8) + (pi)/(4))` `= a sin ((3PI)/(2)) =-a ` `(7) At t = (6T)/(t), y = a sin ((2pi )/(T) xx (6T)/(8) + (pi)/(4))` `= a sin ((7pi)/(4)) =a sin (2pi - (pi)/(4)) =- (a)/(sqrt2)` `(8) At t = (7T)/(8), y = a sin ((2pi)/(T) xx (7T)/(8) + (pi)/(4))` `= a sin (2pi) =0` `(9) A t t = (8T)/(8) =T,y = a sin ((2pi )/(T) xx T + (pi)/(4))` `=a sin ((pi)/(4)) = (a)/(sqrt2) ` From above calculations, graph of `y to t` can be plotted as follows : At `t =0,` initial phase of a particle at distance x is [from equation (2)], `theta = 0.018 x + (pi)/(4)` `implies ` For first particle, `x = 0 implies theta _(1) = (pi)/(4) rad` For SECOND particle, `x =4 cm implies theta_(3) =0.072 + (pi)/(4) rad` For all of above particles wa can draw graph of `y to t ` as shown earlier. For all of them, amplitude, frequency and wavelength are same, but their initial phase are different.

Discussion

13247.	An air bubble of radius 2 mm is at a depth of 5 cm below the free surface of a liquid of surface tension 0.06 N/m and density 1000 kg/m""^(3). The pressure inside the bubble is greater than the atmospheric pressure by n xx 140 "N/m"^(2). Find the value of n.
Answer» Solution :`R=2 MM =2 xx 10^(-3)m` `S=0.007 N//m` `h=5 CM =5 xx 10^(-2)m` `p=1000 kg//m^(3)` `[Pe]=(2S)/(r)+hpg` `=(2 xx 0.07)/(2 xx 10^(-3)) +5 xx 10^(-2) xx 1000 xx 9.8` `=70+490=560N//m^(2)`

Discussion

13248.	The shape of an ancient water clock jug is such that water level descends at a constant rate at all time. If the water level falls by 4cm every hour, determine the shape of the jar, i.e. specify x as a function of y. The radius of drain hole in 2mm and can be assumed to be very small compared to x.
Answer» Solution :`a sqrt(2gy)=pix^(2)(-(dy)/(DT))` Here, `-(dy)/(dt)=(4XX10^(-2))/(3600)=1.11xx10^(-5) m//s` `a=pir^(2)=pi (2XX10^(-3))^(2)` `=1.26xx10^(-5)m^(2)` substituting these values in Eq, (i) we have `(1.26xx10^(-5))sqrt(2xx9.8xxy)=pi (1.11xx10^(-5))x^(2)` or, `y=0.4x^(4)` This is the desired x-y relation.

Discussion

13249.	A body of mass m is pushed up with a velocity u along a plane of inclination theta. If coefficient of friction between the body and the inclined plane is mu displacement of the body before coming to rest is
Answer» `(U^(2)MU)/(2gsintheta)` `(u^(2)mu)/(2gcostheta)` `(u^(2))/(4gsintheta)` `(u^(2))/(2gcostheta)` ANSWER :C

Discussion

13250.	Calculate the linear acceleration of a particle of a particle moving in a circle of radius 0.4 m at the instant when its angular velocity is 2 rad s^(-1) and its angular acceleration is 5 rad s^(-2).
Answer» ANSWER :`[2.6 MS^(-2), 38^(@) 40' " with "a_(t)]`

Discussion

Explore topic-wise InterviewSolutions in .

Proveimpulse momentum equation

If a body of mass m is taken out from a point below the surface of earth equal to half the radius of earth, R, to a height R above the earths surface, then work done on it will be_____mgr

Two particles are projected with same velocity but at angles of projection 35^(@) and 55^(@). Then their horizontal ranges are in the ratio of

If the tension in the cable supporting an elevator is equal to the weight of the elevator, the elevator may be (a) gaoing up with increasing speed(b) going down with increasing speed(c ) going up with uniform speed(d) going down with uniform speed

A block of wood weighs 12 kg and has a relative density 0.6. It is to be in water with 0.9 of its volume immersed. What weight of a metal is needed (a) if the metal is on the top of wood, (b) if the metal is attached below the wood? [RD of metal =14]

A small mass m is transferred from the centre of a hollow sphere of mass M to infinity. Find work done in the process. Compare this with the situation if instead of a hollow sphere, a solid sphere of same mass were there.

Solar constant and Stefan's constant have same dimensions in

A body is sliding down an inclined plane having coefficient of friction 0.5. If the normal reaction is twice that of the resultant downward force along the inclination the angle between the inclined plane and the horizontal is

An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork of frequency 256 Hz, if the length of the column in centimeter is (velocity of sound inair 340 m/s)

A moving blockhaving mass m , collides with another stationary block having mass 4m , The lighter block comes to rest after collision . When the intial velocity of the lighter block is v, then the value of coefficient of restitution (e ) will be

Earth (uniform solid sphere of Mass M Radius rotaes about its North pole - south pole diameter at a constant angular velocity omega. A small block of mass m kept at a colatitude of theta doesn'tslip on earth's surface Then which of the following statements is INCORRECT ?

A uniform disc of mass 2kg and radius 1m is mounted on an axle supported on fixed frictionless bearings. A light cord is wrapped around the rim of the disc and mass of 1kg is tied to the free end. If it is released from rest,

Two bodies having the same mass 2kg each have different surface areas 50 m^(2) and 100 m^(2) in contact with a horizontal plane. If the coefficient of friction is 0.2, the forces of friction that come into play when they are in motion will be in the ratio

The linear magnification is produced by a telescope having an objective of 50cm and eyepiece of 5cm focal length when used to read a scale 3m away is

A car weighing 100 kg is on a slope that makes an angle 30^(@) with the horizontal. The component of car.s weight parallel to the slop is(g = 10ms^(-2))

A satellite A of mass m is at a distance of r from the surface of the earth. Another satellite B of mass 2m is at a distance of 2r from the earth's centre. Their time periods are in the ratio of

Wave equation for one progressive harmonic wave isy = 10 ^(-4) sin (600 t - 2x + (pi)/(3))m and t is in s). Velocity of the wave would be ...... m/s

A gas obeys PV^2= constant in addition to PV =RT. If on heating, the temperature is doubled, the volume of the gas is

China wares are wrapped in straw paper before packing. Why?

Find the dimensions of (i) force (ii) surface tension and (iii) momentum in terms of frequency, velocity and density as fundamental units.

Define unit of a physial quantity.

Which is most elastic?

If the acceleration due to gravity on the moon is one-sixth of that on the earth. What will be the change in length of a second pendulum there so that it may beat a second there ? Take acceleration due to gravity on earth surface =9.8 ms^(-2).

Express Ok on Fahrenheit scale.

At highest point acceleration of projectile is zero.

A thermodynamic process of one mole ideal monoatomic gas is shown in figure. The efficiency of cyclic process ABCA will be

When an air bubble moves up from the bottom of a lake a) velocity decreases and becomes zero b) acceleration increases and becomes zero c) velocity increases and becomes constant d) acceleration decreases and becomes zero

A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration a_(c) is varying with time t as a_(c )= k^(2) rt^(2) where k is a constant. What is the power delivered to the particle by the forces acting on it?

If the coefficient of friction of a surface is sqrt 3, then the angle of inctination of the plane to make a body on it just to slide is

A uniform rope of length .L. and linear density .mu. is on a smooth horizontal table with a lentht .l. lying on the table. The work done in pulling the hanging part on to the table is

A body of mass 3 kg is moving along a straight line with a velocity of 24 ms^(-1). When it is at a point ‘P’ a force of 9 N acts on the body in a direction opposite to its motion. The time after which it will be at 'P' again is,

Four holes of radius R are cut fro a thin square plate of side 4R and mass M. The moment of inertia of the remaining portion about z-axis is ((x)/(3)-(10pi)/(16))"MR"^(2) where 'x' is

About what axis would a uniform cube have its minimum moment of inertia?

A constant force is applied on a 10kg mass at rest. The ratio of works done is 1st, 2nd and 3rd seconds is

A particle moves in x-y plane according to the law x = 4 sin 6t and y=4(1-cos6t). The distance traversed by the particle in 4 seconds is (x and y are in meters)

A uniform solid cylindrical roller of mass 'm' is being pulled on a horizontal surface with force F parallel to the surface and applied at its centre. If the acceleration of the sylinder is 'a and it is rolling without slipping then the value of 'F' is :

Equal torques are applied on acylinder and a sphere. Both have same mass and radius rotates about its axis and sphere rotates about one of its diameter. Which will rotates acquire greater speed and why?

Consider the situation shown in figure. Initially the spring is unstretched when the system is released from rest. Assuming no friction in the pulley, find the maximum elongation of the spring?

If the momentum of a body decreas by 30% its kinetic energy decreases by

For the wave discribed in Exercise 15.8, plot the displacement (y) versus (t) graphs for x=0, 2 and 4 cm. What are the shapes of these graphs ? In which aspects does the oscillatory motion in travelling wave differ from one point to another: amplitude, frequency or phase ?

An air bubble of radius 2 mm is at a depth of 5 cm below the free surface of a liquid of surface tension 0.06 N/m and density 1000 kg/m""^(3). The pressure inside the bubble is greater than the atmospheric pressure by n xx 140 "N/m"^(2). Find the value of n.

The shape of an ancient water clock jug is such that water level descends at a constant rate at all time. If the water level falls by 4cm every hour, determine the shape of the jar, i.e. specify x as a function of y. The radius of drain hole in 2mm and can be assumed to be very small compared to x.

A body of mass m is pushed up with a velocity u along a plane of inclination theta. If coefficient of friction between the body and the inclined plane is mu displacement of the body before coming to rest is

Calculate the linear acceleration of a particle of a particle moving in a circle of radius 0.4 m at the instant when its angular velocity is 2 rad s^(-1) and its angular acceleration is 5 rad s^(-2).