IIT JEE , AIEEE Forum - Physics , Mechanics - inertia

sinjan.j

please see the pic and answer my question.

question is there in the pic itself.

astronautameya

as i said for the athelete, even here, the ball when thrown up, has a horizontal velocity equal to the velocity of the train. so, it continues to move horizontally with that velocity, while still carrying out its vertical motion. this is explained by the inertia of the ball.
but if the train were either acc. or deccelerating, it wudnt hold true.

rate if satisfied

spideyunlimited

correct astronautameya.
horizontal velocity acquired by the ball is same as that of train. thus relative displacement along horizontal direction is 0 the only displacement is in the vertical direction. ie. up and down. so ball thrown up comes back down to the hand of the person..the distance actually travelled by the ball is equal to that travelled by the man hence relatively its just simple vertical motion

sankydreams

Here u must note that if there were no air inside the carriage the ball wudnt have come back
coz when the train moves the entire atmosphere in the train moves with the same velo and accn
thatz also why the above observation doesnt hold true when the ball is thrown outside the window coz there is an additional component of force acting

spideyunlimited

no ur wrong @sankydreams
... the ball will come back even if the train's interior is a vacuum.
because the ball when thrown acquires the same velocity as the person's hand which is the same as the train.
when the ball is thrown out also the ball with move with same velocity in horizontal direction till its height reaches 0 due to g... the train is not accelerating. it's moving with constant velocity

rahulsharma3154

spidey unlimited is correct

astronautameya

no... sanky has a point, which we generally choose to ignore....
the air drag!

but realistically, spidey is totally right......

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