11Which is heavier . That is important for taking decisions
hey guys!
there is a very popular problem... but the thing is dat i for go the trick ...
two masses m1 and m2.. and a massless pulley... as usual..
theya re moving wid some acceleration..
the thing is : let m1 be stopped for an instant..
then wat are the consequences ??
like after wat time the string will be taut??
and include all other consequences that u all think can happen.............
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7 Answers
11If m1 is stopped the string will be taut the very next second since m1 was being pulled by m2
11if we consider m1>m2
Then m1 is pulling m2. Since m1 stops it stops pulling m2. m2 will be having a velocity as it was accelerated by m1 before it stopped. The velocity is upwards. Therefore the string will become taut again after v becomes v(with opposite direction.
1for m1>m2
well just before stopping they will have their velocities equal=v
when m1 is stopped its velocity goes to zero
then the tension vanishes and regains again when distance between them = length of thread again
after stopping m1 faces g downwards with zero velocity
m2 also faces g downwards with v velocity upwards
so let the string become taut after time t
vt-(1/2)gt2=1/2gt2
In this way we can obtain the time
also if the lighter mass is stopped in the above case
we have (let t again be time of tension regain)
vt+1/2gt2+1/2gt2=0
which gives t=0 which means the string will instantly become taut
