
#1
Jan813, 03:45 AM

P: 5

dV/dS*v=a
now at the higest point when we throw a ball. v=0 which implies a=0 but that is npot true....any expanations? 



#2
Jan813, 03:58 AM

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P: 26,167

hi carhah! welcome to pf!
(draw a graph of v against t) 



#3
Jan813, 04:04 AM

P: 5

but if we put v=0 in equationdV/dS*v=a
we get a=0? i am in doubt... 



#4
Jan813, 04:06 AM

P: 5

dV/dS*v = abut if we put v=0 in equationdV/dS*v=a 



#5
Jan813, 04:26 AM

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hi carhah!
(you don't need to send a pm … everyone gets automatic email notification of any new post in any thread they've posted in ) eg, if a is constant, and if s_{o} = v_{o} = 0, then s = 1/2 at^{2} and v = at, so v = √(2as), so dv/ds_{t=0} = √(a/s_{o})= √(a/0) = ∞ 



#6
Jan813, 04:35 AM

P: 5

thanks tim :D BUT DOES that mean that we cannot apply that formula a=dv/ds*v in case of constant acceleration. :) 



#7
Jan813, 04:42 AM

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but if it says a = ∞*0, that doesn't help very much! 



#8
Jan813, 05:02 AM

P: 5

can u draw graph of dv/ds ? and prove it is infinity?



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