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Microzero
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A train moves in a straight at a constant speed u. A boy on the train throw a ball of mass m straight ahead, along the motion of the train, with a speed v with respect to himdelf.
a)What is the KE gain of the ball measured by the boy?
b)What is the KE gain of the ball measured by a man standing by the railroad track?
c)How much work is done by the boy throwing the ball?
d)How much work is done by the train?
a) 1/2 mv^2
b) 1/2m(v+u)^2 - 1/2 mu^2 = 1/2mv^2 +muv
c) measured by the boy: 1/2 mv^2 , measured by the man: 1/2 mv^2
d) measured by the boy: 0 , measured by the man: muv
My fd suggest that there is no workdone by the boy measured by the man, all work is done by the train.
Is there anything wrong in part c and d?
Plz tell me why if I am wrong
a)What is the KE gain of the ball measured by the boy?
b)What is the KE gain of the ball measured by a man standing by the railroad track?
c)How much work is done by the boy throwing the ball?
d)How much work is done by the train?
a) 1/2 mv^2
b) 1/2m(v+u)^2 - 1/2 mu^2 = 1/2mv^2 +muv
c) measured by the boy: 1/2 mv^2 , measured by the man: 1/2 mv^2
d) measured by the boy: 0 , measured by the man: muv
My fd suggest that there is no workdone by the boy measured by the man, all work is done by the train.
Is there anything wrong in part c and d?
Plz tell me why if I am wrong
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