A ball A is dropped from a building of height 45 m. Simultaneously another identical ball B is thrown up with a speed 50 m s^{−1}. The relative speed of ball B w.r.t. ball A at any instant of time is (Take g = 10 m s^{−2}).
A ball A is thrown up vertically with a speed u and at the same instant another ball B is released from a height h. At time t, the speed of A relative to B is
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Two cars A and B are running at velocities of 60 km h^{−1} and 45 km h^{−1}. What is the relative velocity of car A with respect to car B, if both are moving eastward?
Two cars A and B are running at velocities of 60 km h^{−1} and 45 km h^{−1}. What is the relative velocity of car A with respect to car B, if car A is moving eastward and car B is moving westward?
On a twolane road, car A is travelling with a speed of 36 km h^{1}. Two cars B and C approach car A in opposite directions with a speed of 54 km h^{1} each. At a certain instant, when the distance AB is equal to AC, both being 1 km, B decides to overtake A before C does. The minimum required acceleration of car B to avoid an accident is
A bird is tossing (flying to and fro) between two cars moving towards each other on a straight road. One car has speed of 27 km h^{−1} while the other has the speed of 18 km h^{−1}. The bird starts moving from first car towards the other and is moving with the speed of 36 km h^{−1} when the two were separated by 36 km. The total distance covered by the bird is
A police van moving on a highway with a speed of 30km h^{−1 }fires a bullet at a thief's car speeding away in the same direction with a speed of 192km h^{−1}. If the muzzle speed of the bullet is 150ms^{−1} , with what relative speed does the bullet hit the thief's car?
A bus is moving with a speed of 10ms^{−1} on a straight road. A scooterist wishes to overtake the bus in 100s. If the bus is at a distance of 1km from the scooterist with what speed should the scooterist chase the bus?
Two towns A and B are connected by a regular bus service with a bus leaving in either direction every T minutes. A man cycling with a speed of 20 kmh^{1} in the direction A to B notices that a bus goes past him every 18 min in the direction of his motion, and every 6 min in the opposite direction. The period T of the bus service is
A 175m long train is travelling along a straight track with a velocity 72km−^{1}h. A bird is flying parallel to the train in the opposite direction with a velocity 18km^{−1}h. The time taken by the bird to cross the train is
Two parallel rail tracks run northsouth. On one track train A moves north with a speed of 54kmh^{−1} and on the other track train B moves south with a speed of 90kmh^{−1}. The velocity of train A with respect to train B is
Two parallel rail tracks run northsouth. On one track train A moves north with a speed of 54 kmh^{−1} and on the other track train B moves south with a speed of 90kmh^{−1}. What is the velocity of a monkey running on the roof of the train A against its motion with a velocity of 18 kmh^{1} with respect to the train A as observed by a man standing on the ground?
A train A which is 120m long is running with velocity 20m/s while train B which is 130m long is running in opposite direction with velocity 30m/s. What is the time taken by train B to cross the train A?
A jet airplane travelling at the speed of 500kmh^{−1} ejects its products of combustion at the speed of 1500kmh^{−1 }relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is
On a long horizontally moving belt, a child runs to and fro with a speed 9kmh^{−1} (with respect to the belt) between his father and mother located 50m apart on the moving belt. The belt moves with a speed of 4kmh^{−1}. For an observer on a stationary platform, the speed of the child running in the direction of motion of the belt is
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102 videos411 docs121 tests
