Practice Test

Q1) At what minimum altitude should the pilot fly the plane to avoid being hit. Show Answer

Q2) The resultant of two forces 3 P and 2 P is R. If the first force is doubled, then the resultant is also doubled. The angle between the two forces is Show Answer

Q3) Statement 1 : A person can swim in still water with a velocity less than river flow. If he starts swimming perpendicularly to the river velocity observed by stationary frame, the drift of the person is minimum.
Statement 2 : The time spent in river will be minimum, when swimmer swims in the direction perpendicular to the velocity of river. Show Answer

Q4) The time of flight of a projectile on an upward inclined plane depends upon Show Answer

Q5) Statement 1 : A swimmer is swimming in the river for the shortest path. His average velocity is perpendicular to the water flow.
Statement 2 : The component of the resultant velocity of swimmer in the direction of flow should be least for shortest path. Show Answer

Q6) The speed of projectile projected from the bottom is Show Answer

Q7) The ratio of the speed of the projectile projected from the top and the speed of the projectile projected from the bottom of tower is Show Answer

Q8) The time of flight of projectiles is Show Answer

Q9) A cyclist turns around a curve at 15 miles/hour. If he turns at double the speed, the tendency to overturn is Show Answer

Q10) If a particle moves in a circle describing equal angles in equal times, its velocity vector Show Answer

Q11) A stone of mass m is tied to a string of length l and rotated in a circle with a constant speed v. If the string is released, the stone flies Show Answer

Q12) A body is moving in a circular path with a constant speed. It has Show Answer

Q13) A motor cyclist going round in a circular track at constant speed has Show Answer

Q14) A particle P is moving in a circle of radius 'a' with a uniform speed v. C is the center of the circle and AB is a diameter. When passing through B the angular velocity of P about A and C are in the ratio Show Answer

Q15) A car moving on a horizontal road may be thrown out of the road in taking a turn Show Answer

Q16) A particle moves with constant angular velocity in a circle. During the motion its Show Answer

Q17) A stone tied to a string is rotated in a circle. If the string is cut, the stone flies away from the circle because Show Answer

Q18) A body is revolving with a constant speed along a circle. If its direction of motion is reversed but the speed remains the same, then which of the following statement is true Show Answer

Q19) When a body moves with a constant speed along a circle Show Answer

Q20) A body of mass m moves in a circular path with uniform angular velocity. The motion of the body has constant Show Answer

Q21) On a railway curve, the outside rail is laid higher than the inside one so that resultant force exerted on the wheels of the rail car by the tops of the rails will Show Answer

Q22) If the overbridge is concave instead of being convex, the thrust on the road at the lowest position will be Show Answer

Q23) A cyclist taking turn bends inwards while a car passenger taking same turn is thrown outwards. The reason is Show Answer

Q24) A car sometimes overturns while taking a turn. When it overturns, it is Show Answer

Q25) A tachometer is a device to measure Show Answer

Q26) Two bodies of mass 10 kg and 5 kg moving in concentric orbits of radii R and r such that their periods are the same. Then the ratio between their centripetal acceleration is Show Answer

Q27) The ratio of angular speeds of minute hand and hour hand of a watch is Show Answer

Q28) A car travels north with a uniform velocity. It goes over a piece of mud which sticks to the tyre. The particles of the mud, as it leaves the ground are thrown Show Answer

Q29) A particle is moving in a horizontal circle with constant speed. It has constant Show Answer

Q30) A train is moving towards north. At one place it turns towards north-east, here we observe that Show Answer

Q31) The angular speed of a fly wheel making 120 revolutions/minute is Show Answer

Q32) A particle is moving on a circular path with constant speed, then its acceleration will be Show Answer

Q33) A mass of 100 gm is tied to one end of a string 2 m long. The body is revolving in a horizontal circle making a maximum of 200 revolutions per min. The other end of the string is fixed at the centre of the circle of revolution. The maximum tension that the string can bear is (approximately) Show Answer

Q34) A road is 10 m wide. Its radius of curvature is 50 m. The outer edge is above the lower edge by a distance of 1.5 m. This road is most suited for the velocity Show Answer

Q35) Certain neutron stars are believed to be rotating at about 1 rev/sec. If such a star has a radius of 20 km, the acceleration of an object on the equator of the star will be Show Answer

Q36) A particle revolves round a circular path. The acceleration of the particle is Show Answer

Q37) The length of second's hand in a watch is 1 cm. The change in velocity of its tip in 15 seconds is Show Answer

Q38) An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 r.p.m. The acceleration of a point on the tip of the blade is about Show Answer

Q39) The force required to keep a body in uniform circular motion is Show Answer

Q40) Cream gets separated out of milk when it is churned, it is due to Show Answer

Q41) A particle of mass m is executing uniform circular motion on a path of radius r. If p is the magnitude of its linear momentum. The radial force acting on the particle is Show Answer

Q42) A particle moves in a circular orbit under the action of a central attractive force inversely proportional to the distance 'r'. The speed of the particle is Show Answer

Q43) The average acceleration vector for a particle having a uniform circular motion is Show Answer

Q44) When a particle moves in a uniform circular motion. It has Show Answer

Q45) A motorcycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motorcycle is ascending on the overbridge, the normal force on it Show Answer

Q46) A mass of 2 kg is whirled in a horizontal circle by means of a string at an initial speed of 5 revolutions per minute. Keeping the radius constant the tension in the string is doubled. The new speed is nearly Show Answer

Q47) The magnitude of the centripetal force acting on a body of mass m executing uniform motion in a circle of radius r with speed v is Show Answer

Q48) A string breaks if its tension exceeds 10 newtons. A stone of mass 250 gm tied to this string of length 10 cm is rotated in a horizontal circle. The maximum angular velocity of rotation can be Show Answer

Q49) A 500 kg car takes a round turn of radius 50 m with a velocity of 36 km/hr. The centripetal force is Show Answer

Q50) A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved Show Answer

Q51) A body of mass 5 kg is moving in a circle of radius 1 m with an angular velocity of 2 radian/sec. The centripetal force is Show Answer

Q52) A stone of mass of 16 kg is attached to a string 144 m long and is whirled in a horizontal circle. The maximum tension the string can withstand is 16 Newton. The maximum velocity of revolution that can be given to the stone without breaking it, will be Show Answer

Q53) The second's hand of a watch has length 6 cm. Speed of end point and magnitude of difference of velocities at two perpendicular positions will be Show Answer

Q54) A sphere of mass m is tied to end of a string of length l and rotated through the other end along a horizontal circular path with speed v. The work done in full horizontal circle is Show Answer

Q55) A body is whirled in a horizontal circle of radius 20 cm. It has angular velocity of 10 rad/s. What is its linear velocity at any point on circular path Show Answer

Q56) In a circus stuntman rides a motorbike in a circular track of radius R in the vertical plane. The minimum speed at highest point of track will be Show Answer

Q57) A block of mass m at the end of a string is whirled round in a vertical circle of radius R. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is Show Answer

Q58) A sphere is suspended by a thread of length l. What minimum horizontal velocity has to be imparted the ball for it to reach the height of the suspension Show Answer

Q59) A bottle of sodawater is grasped by the neck and swing briskly in a vertical circle. Near which portion of the bottle do the bubbles collect Show Answer

Q60) A cane filled with water is revolved in a vertical circle of radius 4 meter and the water just does not fall down. The time period of revolution will be Show Answer

Q61) A 2 kg stone at the end of a string 1 m long is whirled in a vertical circle at a constant speed. The speed of the stone is 4 m/sec. The tension in the string will be 52 N, when the stone is Show Answer

Q62) A body slides down a frictionless track which ends in a circular loop of diameter D, then the minimum height of the body in term D of so that it may just complete the loop, is Show Answer

Q63) A heavy mass is attached to a thin wire and is whirled in a vertical circle. The wire is most likely to break Show Answer

Q64) The maximum velocity at the lowest point, so that the string just slack at the highest point in a vertical circle of radius l Show Answer

Q65) In a vertical circle of radius r, at what point in its path a particle has tension equal to zero if it is just able to complete the vertical circle Show Answer

Q66) The tension in the string revolving in a vertical circle with a mass m at the end which is at the lowest position Show Answer

Q67) A hollow sphere has radius 6.4 m. Minimum velocity required by a motor cyclist at bottom to complete the circle will be Show Answer

Q68) A fan is making 600 revolutions per minute. If after some time it makes 1200 revolutions per minute, then increase in its angular velocity is Show Answer

Q69) A stone is just released from the window of a train moving along a horizontal straight track. The stone will hit the ground following Show Answer

Q70) A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground Show Answer

Q71) An aeroplane is flying at a constant horizontal velocity of 600 km/hr at an elevation of 6 km towards a point directly above the target on the earth's surface. At an appropriate time, the pilot releases a ball so that it strikes the target at the earth. The ball will appear to be falling Show Answer

Q72) A bomb is dropped from an aeroplane moving horizontally at constant speed. When air resistance is taken into consideration, the bomb Show Answer

Q73) A man projects a coin upwards from the gate of a uniformly moving train. The path of coin for the man will be Show Answer

Q74) An aeroplane is flying horizontally with a velocity of 600 km/h at a height of 1960 m. When it is vertically at a point A on the ground, a bomb is released from it. The bomb strikes the ground at point B. The distance AB is Show Answer

Q75) A ball is rolled off the edge of a horizontal table at a speed of 4 m/second. It hits the ground after 0.4 second. Which statement given below is true Show Answer

Q76) If the initial velocity of a projectile be doubled, keeping the angle of projection same, the maximum height reached by it will Show Answer

Q77) In the motion of a projectile freely under gravity, its Show Answer

Q78) The angle of projection at which the horizontal range and maximum height of projectile are equal is Show Answer

Q79) A ball is thrown upwards and it returns to ground describing a parabolic path. Which of the following remains constant Show Answer

Q80) At the top of the trajectory of a projectile, the directions of its velocity and acceleration are Show Answer

Q81) The velocity with which the projectile is projected is Show Answer

Q82) The angle with the horizontal at which the projectile was projected is Show Answer

Q83) The acceleration due to gravity is given by Show Answer

Q84) The greatest height to which a man can throw a stone is h. The greatest distance to which he can throw it, will be Show Answer

Q85) The horizontal range is four times the maximum height attained by a projectile. The angle of projection is Show Answer

Q86) A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by Show Answer

Q87) At the top of the trajectory of a projectile, the acceleration is Show Answer

Q88) A body is projected at such an angle that the horizontal range is three times the greatest height. The angle of projection is Show Answer

Q89) A gun is aimed at a target in a line of its barrel. The target is released and allowed to fall under gravity at the same instant the gun is fired. The bullet will Show Answer

Q90) If the range of a gun which fires a shell with muzzle speed V is R, then the angle of elevation of the gun is Show Answer

Q91) If time of flight of a projectile is 10 seconds. Range is 500 meters. The maximum height attained by it will be Show Answer

Q92) A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that Show Answer

Q93) A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/sec. A plumb bob is suspended from the roof of the car by a light rigid rod of length 1.00 m. The angle made by the rod with track is Show Answer

Q94) Assertion : Two particles of different mass, projected with same velocity at same angles. The maximum height attained by both the particle will be same.
Reason :The maximum height of projectile is independent of particle mass. Show Answer

Q95) Assertion : The maximum horizontal range of projectile is proportional to square of velocity.
Reason :The maximum horizontal range of projectile is equal to maximum height attained by projectile. Show Answer

Q96) Assertion : The trajectory of projectile is quadratic in y and linear in x.
Reason : y component of trajectory is independent of x-component. Show Answer

Q97) Assertion : When a body is dropped or thrown horizontally from the same height, it would reach the ground at the same time.
Reason :Horizontal velocity has no effect on the vertical direction. Show Answer

Q98) Assertion : When the velocity of projection of a body is made n times, its time of flight becomes n times.
Reason : Range of projectile does not depend on the initial velocity of a body. Show Answer

Q99) Assertion : The height attained by a projectile is twenty five percent of range, when projected for maximum range.
Reason : The height is independent of initial velocity of projectile. Show Answer

Q100) Assertion : In order to hit a target, a man should point his rifle in the same direction as target.
Reason : The horizontal range of the bullet is dependent on the angle of projectile with horizontal direction. Show Answer

Q101) Assertion : When a particle moves in a circle with a uniform speed, its velocity and acceleration both changes.
Reason : The centripetal acceleration in circular motion is dependent on angular velocity of the body. Show Answer

Q102) Assertion : During a turn, the value of centripetal force should be less than the limiting frictional force.
Reason : The centripetal force is provided by the frictional force between the tyres and the road. Show Answer

Q103) Assertion : When a vehicle takes a turn on the road, it travels along a nearly circular path.
Reason : In circular motion, velocity of vehicle remains same. Show Answer

Q104) Assertion : As the frictional force increases, the safe velocity limit for taking a turn on an unbanked road also increases.
Reason :Banking of roads will increase the value of limiting velocity. Show Answer

Q105) Assertion : If the speed of a body is constant, the body cannot have a path other than a circular or straight line path.
Reason :It is not possible for a body to have a constant speed in an accelerated motion. Show Answer

Q106) Assertion : In circular motion, work done by centripetal force is zero.
Reason : In circular motion centripetal force is perpendicular to the displacement. Show Answer

Q107) Assertion : In circular motion, the centripetal and centrifugal force acting in opposite direction balance each other.
Reason : Centripetal and centrifugal forces don’t act at the same time. Show Answer

Q108) Assertion : If both the speed of a body and radius of its circular path are doubled, then centripetal force also gets doubled.
Reason : Centripetal force is directly proportional to both speed of a body and radius of circular path. Show Answer

Q109) Assertion : When an automobile while going too fast around a curve overturns, its inner wheels leave the ground first.
Reason : For a safe turn the velocity of automobile should be less than the value of safe limit velocity. Show Answer

Q110) Assertion : A safe turn by a cyclist should neither be fast nor sharp.
Reason : The bending angle from the vertical would decrease with increase in velocity. Show Answer

Q111) Assertion : Improper banking of roads causes wear and tear of tyres.
Reason : The necessary centripetal force is provided by the force of friction between the tyres and the road. Show Answer

Q112) Assertion : Cream gets separated out of milk when it is churned, it is due to gravitational force.
Reason : In circular motion gravitational force is equal to centripetal force. Show Answer

Q113) Assertion : Two similar trains are moving along the equatorial line with the same speed but in opposite direction. They will exert equal pressure on the rails.
Reason : In uniform circular motion the magnitude of acceleration remains constant but the direction continuously changes. Show Answer

Q114) Assertion : A coin is placed on phonogram turn table. The motor is started, coin moves along the moving table.
Reason : The rotating table is providing necessary centripetal force to the coin. Show Answer

Q115) Roads are banked on curves so that Show Answer

Q116) In uniform circular motion Show Answer

Q117) A car is moving with a uniform speed on a level road. Inside the car there is a balloon filled with helium and attached to a piece of string tied to the floor. The string is observed to be vertical. The car now takes a left turn maintaining the speed on the level road. The balloon in the car will Show Answer

Q118) A body is revolving with a uniform speed v in a circle of radius r. The tangential acceleration is Show Answer

Q119) A particle does uniform circular motion in a horizontal plane. The radius of the circle is 20 cm. The centripetal force acting on the particle is 10 N. It's kinetic energy is Show Answer

Q120) A body of mass is suspended from a string of length . What is
minimum horizontal velocity that should be given to the body in its lowest position so that it may complete one full revolution in the vertical plane with the point of suspension as the centre of the circle Show Answer

Q121) If the angular velocity is doubled, keeping radius the same, the new force will be Show Answer

Q122) If the angular velocity is kept same but the radius of the path is halved, the new force will be Show Answer

Q123) If the centripetal force F is kept constant but the angular velocity is doubled, the new radius of the path (original radius R) will be Show Answer

Q124) A body of mass m kg is rotating in a vertical circle at the end of a string of length r metre. The difference in the kinetic energy at the top and the bottom of the circle is Show Answer

Q125) Which one of the following can be zero, when a particle is in motion for some time? Show Answer

Q126) The tyre of a truck completes 2100 revolutions to cover a distance of 8.8 km. What is the diameter of the tyre? Show Answer

Q127) A body starts from rest and moves with a uniform acceleration. The ratio of the distance covered by the body in the nth second of its motion to the total distance travelled in n second is Show Answer

Q128) Two bodies A and B start from the same point at the same instant and move along a straight line. A moves with a uniform acceleration and B moves with a uniform velocity. They meet after time t. What is the value of t? Show Answer

Q129) A car is moving along a straight road with a uniform acceleration. It passes through two points P and Q separated by a distance with velocities 30 km/h and 40 km/h respectively. What is the velocity of the car midway between P and Q? Show Answer

Q130) A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 m/s to 20 m/s while covering a distance of 135 m in t second. What is the value of t? Show Answer

Q131) A body moving along a straight line is covering distances which are directly proportional to the square of the time. What is the acceleration of the body if K is the constant of proportionality? Show Answer

Q132) A person travels 4 m to the north. Then he turns to the right and covers a distance of 6 m. Then he turns to the left and covers a distance of 4 m. How many metre is he away from the starting point? Show Answer

Q133) A body starts from rest, what is the ratio of the distance travelled by the body during the 4th and 3rd second? Show Answer

Q134) A car moving along a straight highway with a speed of 108 km/h, is brought to rest within a distance of 100 m. How long does it take for the car to stop? Show Answer

Q135) A body is moving with uniform acceleration (a) along a straight line. When it travels a distance of 30 m its average velocity is 36 m/s. The change in velocity during this time interval is 15 m/s. What is the value of uniform acceleration? Show Answer

Q136) Speeds of two identical cars are u and 4 u at a specific instant. They are uniformly retarded. What is the ratio of the respective distances at which the two cars are stopped from that instant? Show Answer

Q137) There is a hemispherical bowl of radius R. A block of mass m slides down from the rim of the bowl to the bottom. What is the velocity of the block when it reaches the bottom? Show Answer

Q138) A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 s for every circular round. The average velocity and average speed for each circular round respectively are Show Answer

Q139) A car accelerates from rest at constant rate for first 10 s and covers a distance x. It covers a distance y in next 10 s at the same acceleration. Which of the following is true? Show Answer

Q140) Two trains travelling on the same track are approaching each other with equal speed of 40 m/s. The drivers of the trains begin to decelerate simultaneously when they are just 2 km apart. If the decelerations are both uniform and equal, then the value of deceleration to avoid the collision should be Show Answer

Q141) A 150 m long train having a constant acceleration crosses a 300 m long platform. It enters the platform at a speed of 40 m/s and leaves it at a speed of 50 m/s. What is the acceleration of the train? Show Answer

Q142) The displacement of a body is given to be proportional to the cube of the time elapsed. The magnitude of the acceleration of the body is Show Answer

Q143) A body travels 200 cm in the first 2 s and 220 cm in the next 4 second. What will be its velocity at the end of seventh second from the start? Show Answer

Q144) A car moving with a constant acceleration covers the distance between two points A and B 180 m apart in 6 second. Its speed at the second point B is 45 m/s. What is its speed at the first point A? At what prior distance from the point A was the car at rest? Show Answer

Q145) A body with initial velocity u, is moving with uniform acceleration 'a', along a straight line. The sum of the distances travelled by it in the t th and (t + 1) th seconds is 80 m. What is its velocity at the end of t th second? Show Answer

Q146) The average velocity of a body moving with uniform acceleration after travelling a distance 306 m is 34 m/s. If the change in velocity of the body is 18 m/s, during the time, its uniform acceleration is Show Answer

Q147) A man is at a distance d from a bus, when the bus begins to move with a constant acceleration a. The minimum velocity with which the man should run towards the bus in order to catch it is Show Answer

Q148) A metro train starts from rest and in five seconds achieves a velocity of 108 km/hr. After that it moves with constant velocity and comes to rest after travelling 45 m with uniform retardation. The total distance travelled is 390 m. What is the total time of travelling? Show Answer

Q149) Two bodies A and B move in the same straight line starting from the same position. A moves with a constant velocity u and B moves with a constant acceleration f. What is the distance between them, when their velocities become equal? Show Answer

Q150) A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further it will penetrate before coming to rest assuming that it faces constant resistance to its motion? Show Answer

Q151) A car covers the first-half of the distance between two places at 40 km/h and other half at 60 km/h. The average speed of the car is Show Answer

Q152) A bus travels the first one-third distance at a speed of 10 km/h, the next one-third at 20 km/h and the last one-third at 60 km/h. The average speed of the bus is Show Answer

Q153) A boy walks to his school at a distance of 6 km with a speed of 2.5 km/h and walks back with a constant speed of 4 km/h. What is his average speed for round trip expressed in km/h? Show Answer

Q154) Which one of the following curves does not represent motion in one dimension? Show Answer

Q155) A car moves a distance of 200 m. It covers the first-half of the distance at speed 40 km/h and the second-half of distance at speed v. The average speed is 48 km/h, Find the value of v. Show Answer

Q156) The minute hand of a wall-clock is 10 cm long. What is the average velocity of the tip of the minute hand between 6.00 a.m. to 7.30 a.m.? Show Answer

Q157) A taxi driver wants to go from Mumbai to Pune at an average speed of 60 km/hr. But due to traffic jam, he could cover 1/3 of the distance at 40 km/hr. How fast must he drive on the rest of the highway in order to reach Pune in time? Show Answer

Q158) The area of the acceleration - displacement curve of a body gives Show Answer

Q159) A sphere A, moving with a speed of 5 m/s, in the positive x direction, collides with a stationary bigger sphere B, which is 20 m away from A. After collision with B, A retraces its path and reaches the starting point with a speed of 4 m/s. What is the average velocity of A, during the time interval 0 to 6 s? Show Answer

Q160) A juggler throws the balls in air. How high each ball will rise if he throws n balls per second? Show Answer

Q161) A body is thrown vertically upwards from the ground. It reaches a maximum height of 20 m in 5 s. After what time it will reach the ground from its maximum height position? Show Answer

Q162) A particle (A) is dropped from a height (h) and another particle (B) is projected in the horizontal direction with a speed of 5 m/s from the same height. Then choose the correct statement. Show Answer

Q163) Two bodies A (of mass 1 kg) and B (of mass 3 kg) are dropped from heights of 16 m and 25 m, respectively. What is the ratio of the times taken by them to reach the ground? Show Answer

Q164) A body of mass m dropped from a height (h), with initial velocity zero, strikes the ground with a velocity of 3 m/s. Another body of the same mass is dropped from the same height with an initial velocity of 4 m/s. What is the final velocity of the second body when it strikes the ground? Show Answer

Q165) With what speed a body should be thrown up so that the distances traversed by it in the fifth second and sixth second are equal? Show Answer

Q166) A boy throws the balls vertically up in air in such a way that when the first one is at the highest point, he throws the second. How high each ball will rise, if he throws two balls per second? Show Answer

Q167) Two bodies which are at different heights from the ground, start falling under gravity. The times of fall of the two bodies are 1s and 2s respectively. What is the initial separation between the two bodies? Show Answer

Q168) A stone, dropped from a certain height, can reach the ground in 5 s. It is stopped after 3 seconds of its fall and then allowed to fall again. What is the time taken by the stone to cover the remaining distance? Show Answer

Q169) A body thrown vertically upwards reaches its maximum height in t second. What is the total time from the time of projection to reach a point at half of its maximum height while returning (in seconds)? Show Answer

Q170) If a ball is thrown vertically upwards with speed u, the distance covered by it during the last t second of its ascent is Show Answer

Q171) There is a leakage in the ceiling of a room of height 4m. Drops of water fall regularly from the ceiling in such a way that when the third drop leaves the ceiling, the first drop touches the marble floor. What is the position of the second drop when the third drop just leaves the ceiling? Show Answer

Q172) A body is projected vertically upwards with a velocity u After 1 and 7 s, it crosses a reference point at a height h. What is the value of u? Show Answer

Q173) A stunt man running across a rooftop of a building wants to land on the roof of the next building. The roof is 4.9 m below the first roof and 5 m away from it. What is his minimum jumping speed for safe landing on the roof of the next building? Show Answer

Q174) A 120 m long train is moving in a direction with a speed of 20 m/s. A 130 m long train B moving with a speed of 30 m/s in the opposite direction crosses the first train in a time of Show Answer

Q175) Two bodies A and B get 5 m closer per second while travelling in opposite directions. But if they travel in the same direction, they get 0.6 m closer per second. What are the speeds of A and B? Show Answer

Q176) A train of length 200 m travelling at 30 m/s overtakes another train of length 300 m, travelling at 20 m/s in the same direction. What is the time taken by the first train to pass the second train? Show Answer

Q177) A train of 150 m length is going towards north direction at a speed of 10 m/s. A parrot flies at a speed of 5 m/s towards south direction parallel to the railway track. The time taken by the parrot to cross the train is equal to Show Answer

Q178) A boat is sent across a river with a velocity of 8 km/h. If the resultant velocity of the boat is 10 km/hour, then the velocity of the river water is Show Answer

Q179) A passenger starts walking on an escalator at a speed of 6 km/h relative to the escalator. The escalator is moving at a speed of 3 km/h relative to the ground. The total length of the escalator is 120 m. What is the time taken by the passenger to reach the other end of the escalator? Show Answer

Q180) A bus is moving with a speed of 10 m/s on a straight road. A scooterist wishes to overtake the bus in 100 s. If the bus is at a distance of 1 km ahead of the scooterist, with what speed should the scooterist chase the bus? Show Answer

Q181) A thief is driving a jeep which is moving on a straight road with a speed of 72 km/hour. A police van, is 720 m behind the jeep. With what speed the police van should chase the jeep, so that it can overtake the jeep in one minute? Show Answer

Q182) The speed of a boat is 5 km/hour in still water. It crosses a river of width 1 km along the shortest possible path in 15 min. What is the velocity of river water? Show Answer

Q183) A river is flowing from west to east at a speed of 5 m/minute. A man on the south bank of the river, capable of swimming at 10 m/s, in still water, wants to swim across the river in the shortest time. In which direction should he swim? Show Answer

Q184) A bird is tossing (flying to and fro) between two cars moving towards each other on a straight road. One car has a speed of 18 km/h while the other has the speed of 27 km/h. The bird starts moving from first car towards the other and is moving with the speed of 36 km/h when the two cars were separated by 36 km, what is the total distance covered by the bird? Show Answer