
question_answer1) When a light and a heavy body have equal K.E, then which one has a greater momentum?
A) light body
B) heavy body
C) both have equal momentum
D) uncertain
View Answer play_arrow

question_answer2) In SI system, the unit of P.E. is
A) erg
B) dynecm
C) \[J\]
D) none of these
View Answer play_arrow

question_answer3) Kilowatt hour (\[\text{kWh}\]) represents the unit of
A) power
B) impulse
C) momentum
D) none of these
View Answer play_arrow

question_answer4) When speed of a motor car increases six times, then kinetic energy increases by
A) 6 times
B) 36 times
C) 12 times
D) 24 times
View Answer play_arrow

question_answer5) 1 kWh equals
A) \[\text{36 }\times \text{ 1}{{0}^{\text{2}}}\text{ Joules}\]
B) \[\text{36 }\times \text{ 1}{{0}^{\text{4}}}\text{ Joules}\]
C) \[\text{3}.\text{6 }\times \text{ 1}{{0}^{\text{6}}}\text{ Joules}\]
D) none of these
View Answer play_arrow

question_answer6) When speed of the moving object is doubled its
A) acceleration is doubled
B) momentum becomes four times more
C) K. E. is increased to four times
D) potential energy is increased
View Answer play_arrow

question_answer7) When time taken to complete a given amount of work increases, then
A) power increases
B) power decreases
C) energy increases
D) energy decreases
View Answer play_arrow

question_answer8) When the force applied and the displacement of the body are inclined at \[30{}^\circ \] with each other, then work done is
A) infinite
B) maximum
C) zero
D) unity
View Answer play_arrow

question_answer9) The K.E. of a body in increased most by doubling its
A) mass
B) weight
C) speed
D) density
View Answer play_arrow

question_answer10) The energy required to raise a given volume of water from a well can be
A) mega watts
B) mega newton
C) mega joules
D) kilowatts
View Answer play_arrow

question_answer11) The slope of kineticenergydisplacement curve of a particle in motion is
A) equal to the acceleration of the particle
B) inversely proportional to the acceleration
C) directly proportional to the acceleration
D) none of these
View Answer play_arrow

question_answer12) If a force F is applied on a body and it moves with velocity v, then power will be
A) \[F\times \upsilon \]
B) \[\frac{F}{{{\upsilon }^{2}}}\]
C) \[\frac{F}{\upsilon }\]
D) \[F\times {{v}^{2}}\]
View Answer play_arrow

question_answer13) The displacement \[x\] of a particle moving in one dimension, under the action of a constant force, is related to the time t by the equation,\[t=\sqrt{x}+3\]where \[x\] is in metres and t in seconds. The displacement of the particle when its velocity is zero, is
A) 0
B) 6 m
C) 12m
D) 18m
View Answer play_arrow

question_answer14) The relationship between force and position is shown in the figure (in One dimensional case). Work done by the force is displacing a body from \[x\] = 1 cm to \[x\] = 5 cm is
A) 700 ergs
B) 70 ergs
C) 60 ergs
D) 20 ergs
View Answer play_arrow

question_answer15) Work done by a centripetal force
A) increases by decreasing the radius of the circle
B) decreases by increasing the radius of the circle
C) increases by increasing the mass of the body
D) is always zero
View Answer play_arrow

question_answer16) A 1 kg mass falls from a height of 10 m into a sand box. What is the speed of the mass just before hitting the sand box? If it travels a distance of 2 cm into the sand before coming to rest, what is the average retarding force?
A) 12 m/sec and 3600N
B) 14 m/sec and 4900N
C) 16 m/sec and 6400N
D) 18 m/sec and 8100N
View Answer play_arrow

question_answer17) Work done in moving a 50 kg block through a horizontal distance of 10 m by applying a force of 100N which makes an angle of \[60{}^\circ \] with the horizontal is
A) 200 joules
B) 425 joules
C) 500 joules
D) 575 joules
View Answer play_arrow

question_answer18) A particle of mass 4 m which is at rest and explodes into three fragments. Two of the fragments each of mass \[m\] are found to move with a speed \[\upsilon \] in mutually perpendicular directions. The total energy released in the explosion is
A) \[\text{2m}{{\upsilon }^{\text{2}}}\]
B) \[\frac{1}{2}\text{ m}{{\upsilon }^{\text{2}}}\]
C) \[\text{m}{{\upsilon }^{\text{2}}}\]
D) \[\frac{3}{2}\text{m}{{\upsilon }^{\text{2}}}\]
View Answer play_arrow

question_answer19) \[kWh\] is the unit of
A) force
B) power
C) time
D) energy
View Answer play_arrow

question_answer20) A man throws the bricks to the height of 12 m where they reach with a speed of 12 m/s. If he throws the bricks such that they just reach this height, then what percentage of energy will he save?
A) 19%
B) 38%
C) 57%
D) 76%
View Answer play_arrow

question_answer21) The potential energy of a certain spring when stretched through a distance 'S' is 10 joules. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance "S" will be
A) 30
B) 40
C) 10
D) 20
View Answer play_arrow

question_answer22) Two bodies with masses \[{{M}_{A}}\] and \[{{M}_{B}}\] are moving with equal kinetic energy. Their linear momenta are numerically in a ratio \[\left {{P}_{A}} \right:\left {{P}_{B}} \right\], will be
A) \[{{M}_{B}}:{{M}_{A}}\]
B) \[{{M}_{A}}:{{M}_{B}}\]
C) \[\sqrt{{{M}_{A}}}:\sqrt{{{M}_{B}}}\]
D) \[{{M}_{A}}^{2}:{{M}_{B}}^{2}\]
View Answer play_arrow

question_answer23) A ball is allowed to fall from a height of 10 there is 40% loss of energy due to impact, after one impact ball will go upto
A) 10 m
B) 8 m
C) 4m
D) 6m
View Answer play_arrow

question_answer24) Mechanical work done is equal to (symbols have their usual meanings)
A) \[W=\frac{F}{S}\]
B) \[W=FS\]
C) \[W=F+S\]
D) \[W=FS\]
View Answer play_arrow

question_answer25) A body at rest can have
A) speed
B) energy
C) momentum
D) velocity
View Answer play_arrow

question_answer26) An elevator is designed to lift a load of 1000 kg, through 6 floors of a building averaging \[\text{3}\text{.5 m}\]per floor in 6 sec. Power of the elevator, neglecting other losses, will be
A) \[\text{3}\text{.43 }\times \text{ 1}{{0}^{\text{4}}}\text{ watt}\]
B) \[\text{4}\text{.33 }\times \text{ 1}{{0}^{\text{4}}}\text{ watt}\]
C) \[\text{2}\text{.21 }\times \text{ 1}{{0}^{\text{4}}}\text{ watt}\]
D) \[\text{5}\text{.65 }\times \text{ 1}{{0}^{\text{4}}}\text{ watt}\]
View Answer play_arrow

question_answer27) A car of mass 2000 kg is to be stopped from a speed of 72 km/hr. If the coefficient of friction between tyres and road is 0.4, then distance travelled before coming to rest is \[\left( \text{g }=\text{ 1}0\text{ m}/{{\text{s}}^{\text{2}}} \right)\]
A) 25 m
B) 50 m
C) 75 m
D) 100 m
View Answer play_arrow

question_answer28) Which of the following physical quantity is different from others?
A) Work
B) Kinetic energy
C) Force
D) Potential energy
View Answer play_arrow

question_answer29) When a body is whirled in a circle, then work done on it is
A) positive
B) negative
C) zero
D) infinite
View Answer play_arrow

question_answer30) A tennis ball dropped from a height of 2 m rebounds only 1.5 m after hitting the ground. What fraction of energy is lost in the impact?
A) \[\frac{1}{4}\]
B) \[\frac{1}{8}\]
C) \[\frac{1}{2}\]
D) \[\frac{1}{16}\]
View Answer play_arrow

question_answer31) A crane is used to lift 1000 kg of coal from a mine 100 m deep. If the time taken by the crane is 1 hr then find the power of the crane, assuming the efficiency of the crane to be 80%. \[\left( \text{g }=\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}} \right)\]
A) 2567 watts
B) 2403 watts
C) 3403 watts
D) 3761 watts
View Answer play_arrow

question_answer32) A uniform chain of length L and mass M is lying on a smooth table and onethird of its length is hanging vertically down over the edge of the table. If g is acceleration due to gravity, then work required to pull the hanging part on to the table is
A) \[MgL\]
B) \[\frac{MgL}{3}\]
C) \[\frac{MgL}{9}\]
D) \[\frac{MgL}{18}\]
View Answer play_arrow

question_answer33) Unit of power is
A) watt per second
B) joule
C) watt
D) none of these
View Answer play_arrow

question_answer34) The mass of an object P is double the mass of object \[Q\]. If both move with the same velocity, then ratio of K.E. of \[P\] to \[Q\] is
A) 1: 2
B) 2 : 1
C) 1 : 4
D) 4 : 1
View Answer play_arrow

question_answer35) 1 hp is equal to
A) 0.746 kW
B) 7.46 kW
C) 74.6 kW
D) 746 kW
View Answer play_arrow

question_answer36) A truck can move up a road having the grade of 1 m rise for every 50 m with a speed of 15 km/hr. The resisting force is equal to \[\frac{1}{25}\] th the weight Au of the truck. How fast will the same truck move down the hill with the same horse power?
A) 30 km/hr
B) 45 km/hr
C) 60km7hr
D) 75 km/hr
View Answer play_arrow

question_answer37) A bullet is fired at a target with a velocity 80 m/s and penetrates 50 cm into it. If this bullet were fired into a target 25 cm thick with equal velocity, with what velocity would it emerge, supposing the resistance to be uniform and the same in both the cases?
A) \[\sqrt{80}m/s\]
B) \[\frac{40}{\sqrt{2}}m/s\]
C) \[40m/s\]
D) \[40\sqrt{2}m/s\]
View Answer play_arrow

question_answer38) A body of mass 1 kg strikes elastically with another body at rest and continues to move in the same direction with one fourth the initial velocity. The mass of the other body is
A) 3 kg
B) 0.6kg
C) 2.4kg
D) 4kg
View Answer play_arrow

question_answer39) A body rolling down a hill has
A) K.E. only
B) RE. only
C) neither K.E. nor RE.
D) both [a] and [b]
View Answer play_arrow

question_answer40) A stretched spring possesses
A) kinetic energy
B) elastic potential energy
C) electric energy
D) magnetic energy
View Answer play_arrow

question_answer41) If L, M denote the angular momentum and mass of a particle and p its linear momentum. Which of the following can represent the kinetic energy of the particle moving in a circle of radius R?
A) \[\frac{{{L}^{2}}}{2M}\]
B) \[\frac{{{P}^{2}}}{M}\]
C) \[\frac{{{L}^{2}}}{2M{{R}^{2}}}\]
D) \[\frac{1}{2}Mp\]
View Answer play_arrow

question_answer42) A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to
A) \[{{t}^{\frac{3}{2}}}\]
B) \[{{t}^{\frac{1}{2}}}\]
C) \[{{t}^{\frac{3}{4}}}\]
D) \[{{t}^{2}}\]
View Answer play_arrow

question_answer43) A machine, which is 75 percent efficient uses 12 joules of energy in lifting up a 1 kg mass through a certain distance. The mass is then allowed to fall through that distance. What will its velocity be at the end of its fall?
A) \[\sqrt{\text{32}}\text{ m}/\text{s}\]
B) \[\sqrt{\text{24}}\text{ m}/\text{s}\]
C) \[\sqrt{\text{l8}}\text{ m}/\text{s}\]
D) \[\sqrt{\text{9}}\text{ m}/\text{s}\]
View Answer play_arrow

question_answer44) When a person climbs a hill, he possesses
A) only K.E.
B) only RE.
C) both K.E. and RE.
D) none of these
View Answer play_arrow

question_answer45) A particle of mass m moves in a circular orbit of radius r under in action of an attractive force \[\frac{{{K}^{2}}}{{{r}^{2}}}\] which always acts towards the centre r of the orbit. What is the total energy in the particle?
A) \[\frac{k}{{{r}^{2}}}\]
B) \[\frac{2k}{r}\]
C) \[\frac{{{k}^{2}}}{r}\]
D) \[\frac{k}{2r}\]
View Answer play_arrow

question_answer46) Which of the following graphs closely represents the kinetic energy (K) of a freely falling body and its height (h) above the ground?
A)
B)
C)
D)
View Answer play_arrow

question_answer47) A stone of mass m kg is whirled in a vertical circle of radius 20 cm. The difference in the kinetic energies at the lowest and the topmost positions is
A) 4 mg joules
B) 0.4 mg joules
C) 40 mg joules
D) None of these
View Answer play_arrow

question_answer48) The bag of sand of mass 2 kg is suspended by a rope. A bullet of mass 10 g is fired at it and gets embedded into it. The bag rises up a vertical height of 10 cm. The initial velocity of the bullet is nearly
A) 70 m/s
B) 140 m/s
C) 210 m/s
D) 280 m/s
View Answer play_arrow

question_answer49) Which of the following graphs closely represents the P.E (U) of a freely falling body and its height (h) above the ground?
A)
B)
C)
D)
View Answer play_arrow

question_answer50) A rope ladder with a length 1 carrying a man with a mass m at its end is attached to the basket of balloon with a mass M. The entire system if equilibrium in the air. As the man climbs up the ladder into the balloon, the balloon descend by a height h. Then the potential energy of the man
A) increases by \[mg\]\[\left( \text{1}\text{h} \right)\]
B) increases b \[mgl\]
C) increases by \[mgh\]
D) increases by mg \[(2lh)\]
View Answer play_arrow

question_answer51) In question No. 50, the potential energy of the balloon
A) decreases by \[mgh\]
B) increases by \[mgh\]
C) increases by \[mg(1h)\]
D) increases by \[mgl\]
View Answer play_arrow

question_answer52) In question No. 50, the work down by the man is
A) \[mgl\]
B) \[mgh\]
C) \[\frac{1}{2}mgl\]
D) \[mg(1h)\]
View Answer play_arrow

question_answer53) The heart of a man pumps 4000 c.c. of blood through the arteries/per minute at a pressure of 130 mm Hg. If the density of mercury is\[13.6\times {{10}^{3}}\,kg/{{m}^{3}}\], what is the power of heart?
A) \[1.15\] watt
B) \[2.30\]watt
C) \[1.15\] H.P
D) \[0.115\] H.P
View Answer play_arrow

question_answer54) Once a choice made regarding zero potential energy reference state, the changes in potential energy
A) are same
B) are different
C) depend strictly on the choice of the zero potential
D) become in determine
View Answer play_arrow

question_answer55) Two spheres of the same diameter, one of mass 5 kg and the other of 1 kg are dropped at the same time from the top of a tower. When they are 1 metre above the ground the two sphere have the same
A) momentum
B) kinetic energy
C) potential energy
D) acceleration
View Answer play_arrow

question_answer56) It is easier to draw a Wooden block along an inclined plane than to rise it vertically, because
A) friction decreased
B) only part of the weight is to be overcome
C) g is decreased
D) none of the above
View Answer play_arrow

question_answer57) A bag P (mass M) hangs by a long thread and a bullet (mass m) comes horizontally with velocity v and gets caught in the bag. Then for the combined (bag + bullet) system
A) momentum is \[\frac{m\upsilon M}{M+m}\]
B) kinetic energy is \[\frac{m{{V}^{2}}}{2}\]
C) momentum is \[\frac{m\upsilon (M+m)}{M}\]
D) kinetic energy is \[\frac{{{m}^{2}}{{v}^{2}}}{2(M+m)}\]
View Answer play_arrow

question_answer58) The work down in time t on a body of mass m which is accelerated from rest to a speed \[{{v}_{1}}\] in time \[{{t}_{1}}\] as a function of time t is given by
A) \[\frac{1}{2}m\frac{{{\upsilon }_{1}}}{{{t}_{1}}}{{t}^{2}}\]
B) \[m\frac{{{\upsilon }_{1}}}{{{t}_{1}}}{{t}^{2}}\]
C) \[\frac{1}{2}{{\left( \frac{m{{\upsilon }_{1}}}{{{t}_{1}}} \right)}^{2}}{{t}^{2}}\]
D) \[\frac{1}{2}m{{\frac{{{\upsilon }_{1}}}{{{t}_{1}}}}^{2}}{{t}^{2}}\]
View Answer play_arrow

question_answer59) A neutron travelling with a velocity v and kinetic energy E collides perfectly elastically head on with the nucleus of an atom of mass number A at rest. The fraction of total energy retained by the neutron is
A) \[{{\left( \frac{A1}{A+1} \right)}^{2}}\]
B) \[{{\left( \frac{A+1}{A1} \right)}^{2}}\]
C) \[{{\left( \frac{A1}{A} \right)}^{2}}\]
D) \[{{\left( \frac{A+1}{A} \right)}^{2}}\]
View Answer play_arrow

question_answer60) A moving body with a mass \[{{m}_{2}}\]\[{{m}_{1}}\] strike a stationary body of mass \[{{m}_{2}}\]. The masses \[{{m}_{2}}\]and \[{{m}_{2}}\] should be in the ratio \[\frac{{{m}_{1}}}{{{m}_{2}}}\] so as to decrease the velocity of the first body \[1.5\] times assuming a perfectly elastic impact. Then the ratio \[\frac{{{m}_{1}}}{{{m}_{2}}}\] is
A) \[\frac{1}{25}\]
B) \[\frac{1}{5}\]
C) 5
D) 25
View Answer play_arrow

question_answer61) A particle moving along a line travels a distance of 10 m under the action of a force of 5 N. If the work done is 25 J, then the angle between the force and the direction of motion is
A) \[0{}^\circ \]
B) \[30{}^\circ \]
C) \[45{}^\circ \]
D) \[60{}^\circ \]
View Answer play_arrow

question_answer62) A metre rod of mass 12 kg is pivoted at one end and hangs vertically. It is displaced through an angle of \[60{}^\circ \]. The increase in potential energy is........ Given : \[g=10\,m{{s}^{2}}\]
A) 1 Joule
B) \[1.5\] Joule
C) 3 Joule
D) 6 Joule
View Answer play_arrow

question_answer63) A motor of power P is employed to deliver water at a certain rate from a given pipe. In order to obtain thrice as much water from the same pipe in the same time, another motor of power P' is required. Given:\[\text{g}=\text{9}.\text{3489 m}{{\text{s}}^{\text{2}}}\]Now, the ratio \[P'/P\] equals
A) 27
B) 81
C) 561
D) \[{{\left( \text{9}.\text{3489} \right)}^{\text{3}}}\]
View Answer play_arrow

question_answer64) The angle between the applied force and the momentum at time is
A) \[0{}^\circ \]
B) \[30{}^\circ \]
C) \[60{}^\circ \]
D) \[90{}^\circ \]
View Answer play_arrow

question_answer65) A 500 gm ball is thrown vertically upwards with a kinetic energy 58.8 J. The kinetic energy is reduced to half at a height of.......... metre above the point of throw,
A) 2m
B) 3 m
C) 5m
D) 6 m
View Answer play_arrow

question_answer66) An antiaircraft shell has been fired and it has a kinetic energy\[x\]. It explodes in the air. Then the sum of kinetic energies of all the particles is
A) \[x\]
B) more than \[x\]
C) less than \[x\]
D) zero
View Answer play_arrow

question_answer67) The kinetic energy acquired by a mass m after travelling a fixed distance from rest under the action of constant force is
A) directly proportional to\[\sqrt{m}\]
B) directly proportional to m
C) independent of m
D) directly proportional to \[\frac{1}{\sqrt{m}}\]
View Answer play_arrow

question_answer68) A body of mass M collides against a wall with a velocity V and rebounds with the same speed. Its change of momentum is
A) zero
B) \[MV\]
C) \[2MV\]
D) \[MV\]
View Answer play_arrow

question_answer69) The power of a pump motor is 2 kilowatt. The water raised by the pump per minute to a height of 10 m is nearly
A) 500kg
B) 7000kg
C) 1200kg
D) zero
View Answer play_arrow

question_answer70) A chain is held on a frictionless table with one third of its length hanging over the edge. The total length of the chain is 1 and its mass is m. The work required to pull the hanging part back to the table is
A) \[2mgl\]
B) \[\frac{mgl}{5}\]
C) \[\frac{mgl}{9}\]
D) \[\frac{mgl}{18}\]
View Answer play_arrow

question_answer71) The bob of a simple pendulum (mass m and length1) dropped from a horizontal position strikes a block of the same mass elastically placed on a horizontally frictionless table. The K.E. of the block will be
A) \[2mgl\]
B) \[mgl/2\]
C) \[mgl\]
D) 0
View Answer play_arrow

question_answer72) A mass M is attached to a massless spring of spring constant K. The mass is moved through a distance \[X\] and released. The maximum velocity of the mass is
A) \[\frac{2\pi M}{K}\]
B) \[\frac{K}{Mx}\,\frac{\sqrt{K}}{M}\]
C) \[\frac{\sqrt{K}}{M}\]
D) \[\frac{\sqrt{K}}{Mx}\]
View Answer play_arrow

question_answer73) The kinetic energy of a body is numerically equal to thrice the momentum of the body. The velocity of the body is
A) 2 units
B) 3 units
C) 6 units
D) 9 units
View Answer play_arrow

question_answer74) Which of the following is not a perfectly in elastic collision?
A) Capture of an electron by proton
B) Man jumping on to a moving cart
C) Collision between glass balls
D) A bullet fired into a block of wood such that it is embedded in the wood
View Answer play_arrow

question_answer75) A body of mass m moving with velocity v suffers head on elastic collision with another body of mass 2 m at rest. The ratio of the kinetic energy off colliding body before and after collision is
A) 9:1
B) 12:1
C) 16 : 1
D) 18 : 1
View Answer play_arrow

question_answer76) A body of mass 2 kg is sliding with a constant velocity of 4 m/sec on a frictionless horizontal table. The force required to keep the body movie with the same velocity is
A) \[8N\]
B) \[0\,N\]
C) \[2\times {{4}^{2}}N\]
D) \[\frac{1}{2}N\]
View Answer play_arrow

question_answer77) An open knife edge of mass M is dropped from a height h on a wooden floor. If the blade penetrates S into the wood, the average resistance offered by the wood to the blade is
A) \[Mg\]
B) \[Mg\left( 1+\frac{h}{S} \right)\]
C) \[Mg(1+hS)\]
D) \[mg{{\left( 1+\frac{h}{S} \right)}^{2}}\]
E) None of these
View Answer play_arrow

question_answer78) Consider and elevator moving downwards with an acceleration a. The force exerted by a passenger of mass m on the floor of the elevator
A) \[ma\]
B) \[mamg\]
C) \[mgma\]
D) \[mg+ma\]
View Answer play_arrow

question_answer79) A 60 kg man stands on a spring scale in a list At some instant he finds that the scale reading has changed from 60 kg to 50 kg for a while and then comes back to the original mark , What should he conclude?
A) The lift was in constant motion upwards
B) The lift was in constant motion downwards
C) The lift while in motion upwards, suddenly stopped
D) The lift while in motion downwards, suddenly stopped
View Answer play_arrow

question_answer80) A lift is moving downwards with an acceleration equal to the acceleration due to gravity. A body of mass M kept on the floor of the lift is pulled horizontally. If the coefficient of friction is \[\mu \], then the friction resistance offered by the body is
A) \[Mg\]
B) \[\mu Mg\]
C) \[2\mu Mg\]
D) zero
View Answer play_arrow

question_answer81) In question No. 80, if the lift is moving upwards with a uniform velocity then the frictional resistance offered by the body is
A) \[Mg\]
B) \[\mu Mg\]
C) \[2\mu Mg\]
D) zero
View Answer play_arrow

question_answer82) Three particles A, B and C of equal mass, move with equal speed v along the medians of an equilateral triangle as shown in the figure. They collide at centroid G of the triangle. After collision, A comes to rest and B retracts its path with speed v. What is the speed of C after collision?
A) Zero
B) \[\frac{\upsilon }{2}\]
C) \[v\]
D) \[2v\]
View Answer play_arrow

question_answer83) A body of mass 1 kg rests on a smooth surface. Another body B of mass \[0.2\] kg is placed over A as shown. The coefficient of static between A and B is \[0.15\]. B will begin to slide on A if A is pulled with a force greater than
A) \[1.764N\]
B) \[0.1764N\]
C) \[0.3N\]
D) it will not slide for any F
View Answer play_arrow

question_answer84) A person standing on the floor of an elevator drops a coin. The coin reaches the floor of the elevator in a time \[{{t}_{1}}\] if the elevator is stationary and in tune \[{{t}_{2}}\] if it is moving uniformly, then
A) \[{{t}_{1}}={{t}_{2}}\]
B) \[{{t}_{1}}>{{t}_{2}}\]
C) \[{{t}_{1}}<{{t}_{2}}\]
D) \[{{t}_{1}}<{{t}_{2}}\] or \[{{t}_{1}}>{{t}_{2}}\] depending on whether the left is going up or down.
View Answer play_arrow

question_answer85) In a rocket, fuel burns at the rate of\[1\,Kg\,{{s}^{1}}\]. This fuel is ejected from the rocket with a velocity of\[60\,Km{{s}^{1}}\]. This exerts a force, in newton, on the rocket of
A) \[60\,N\]
B) \[600\,N\]
C) \[6,000\,N\]
D) \[60,000\,N\]
View Answer play_arrow

question_answer86) A man has fallen into a ditch of width d and two of his friends are slowly pulling him out using a light rope and two fixed pulleys as shown in the figure. What is the force (assumed equal for both the friends) exerted by each friends on the slope?
A) \[\frac{mg}{4h}\sqrt{{{d}^{2}}+4{{h}^{2}}}\]
B) \[\frac{mg}{4h}\times d\]
C) \[\frac{mg}{4h}\times \sqrt{{{d}^{2}}+4{{h}^{2}}}\]
D) \[\frac{mgh}{d}\]
View Answer play_arrow

question_answer87) The monkey B shown in figure, is holding on to the tail of the monkey A which is climbing up a rope. The masses of the monkeys A and B are 5 kg and 2 kg respectively. If A can tolerate a tension of 30 N in its tail, what force should it apply on the rope in order to carry the monkey B with it? Take \[\text{g }=\text{ 1}0\text{ m}/{{\text{s}}^{\text{2}}}\]
A) between 50 N and \[80N\]
B) between 30 N and \[80N\]
C) between 70 N and \[150N\]
D) between 60 N and \[90N\]
View Answer play_arrow

question_answer88) A ball comes back after an elastic collision with a wall. If initial momentum of the ball is P, the impulse on the wall after the collision is
A) \[P\]
B) \[2P\]
C) zero
D) \[2P\]
View Answer play_arrow

question_answer89) A bullet of mass 10 gm moving with velocity of 100 m/sec hits a wooden log and penetrates it upto thickness of 5 cm. The resistance force of the log is
A) \[200N\]
B) \[500N\]
C) \[1000N\]
D) \[600N\]
View Answer play_arrow